Introduction

Test Result

Result ID Profile Start time End time Benchmark Benchmark version
xccdf_org.open-scap_testresult_CSCF-RHEL6-MLS CSCF-RHEL6-MLS 2014-07-16 17:32 2014-07-16 17:33 embedded 0.9

Target info

Targets

  • anaconda

Addresses

  • 127.0.0.1
  • 192.168.3.10
  • 192.168.99.10
  • 192.168.8.8
  • 192.168.104.10
  • 192.168.105.10
  • 192.168.106.10
  • 192.168.11.10
  • 192.168.103.10
  • 192.168.100.10
  • 192.168.101.10

Applicable platforms

  • cpe:/o:redhat:enterprise_linux:6

Score

system score max % bar
urn:xccdf:scoring:default 96.79 100.00 96.79%
urn:xccdf:scoring:flat 192.00 194.00 98.97%

Results overview

Rule Results Summary

pass fixed fail error not selected not checked not applicable informational unknown total
192 0 0 0 181 24 0 0 2 399
Title Result
Ensure /var/log/audit Located On Separate Partition pass
Install AIDE pass
Disable Prelinking pass
Build and Test AIDE Database notchecked
Configure Periodic Execution of AIDE notchecked
Install Intrusion Detection Software notchecked
Install Virus Scanning Software notchecked
Add nodev Option to Non-Root Local Partitions pass
Add nodev Option to /tmp pass
Add noexec Option to /tmp pass
Add nosuid Option to /tmp pass
Add nodev Option to /dev/shm pass
Add noexec Option to /dev/shm pass
Add nosuid Option to /dev/shm pass
Disable Modprobe Loading of USB Storage Driver pass
Disable Booting from USB Devices in Boot Firmware notchecked
Disable the Automounter pass
Disable GNOME Automounting pass
Disable Mounting of cramfs pass
Disable Mounting of freevxfs pass
Disable Mounting of jffs2 pass
Disable Mounting of hfs pass
Disable Mounting of hfsplus pass
Disable Mounting of squashfs pass
Disable All GNOME Thumbnailers pass
Verify User Who Owns shadow File pass
Verify Group Who Owns shadow File pass
Verify Permissions on shadow File pass
Verify User Who Owns group File pass
Verify Group Who Owns group File pass
Verify Permissions on group File pass
Verify User Who Owns gshadow File pass
Verify Group Who Owns gshadow File pass
Verify Permissions on gshadow File pass
Verify User Who Owns passwd File pass
Verify Group Who Owns passwd File pass
Verify Permissions on passwd File pass
Verify that Shared Library Files Have Restrictive Permissions pass
Verify that Shared Library Files Have Root Ownership pass
Verify that System Executables Have Restrictive Permissions pass
Verify that System Executables Have Root Ownership pass
Ensure All SGID Executables Are Authorized pass
Set Daemon Umask pass
Disable Core Dumps for All Users pass
Disable Core Dumps for SUID programs pass
Enable Randomized Layout of Virtual Address Space pass
Enable NX or XD Support in the BIOS notchecked
Ensure SELinux Not Disabled in /etc/grub.conf pass
Ensure SELinux State is Enforcing pass
Configure SELinux Policy pass
Ensure No Daemons are Unconfined by SELinux notchecked
Direct root Logins Not Allowed notchecked
Restrict Virtual Console Root Logins pass
Restrict Serial Port Root Logins pass
Verify Only Root Has UID 0 pass
Prevent Log In to Accounts With Empty Password pass
Verify All Account Password Hashes are Shadowed pass
Verify No netrc Files Exist pass
Set Password Minimum Length in login.defs pass
Set Password Maximum Age pass
Set Password Warning Age pass
Set Account Expiration Following Inactivity pass
Assign Expiration Date to Temporary Accounts notchecked
Set Password Retry Prompts Permitted Per-Session pass
Set Password to Maximum of Three Consecutive Repeating Characters notchecked
Set Password Strength Minimum Digit Characters pass
Set Password Strength Minimum Uppercase Characters pass
Set Password Strength Minimum Special Characters pass
Set Password Strength Minimum Lowercase Characters pass
Set Password Strength Minimum Different Characters pass
Limit Password Reuse pass
Set Password Hashing Algorithm in /etc/login.defs pass
Set Password Hashing Algorithm in /etc/libuser.conf pass
Limit the Number of Concurrent Login Sessions Allowed Per User unknown
Set Boot Loader Password pass
Disable Interactive Boot pass
GNOME Desktop Screensaver Mandatory Use pass
Enable Screen Lock Activation After Idle Period pass
Implement Blank Screen Saver pass
Set GUI Warning Banner Text notchecked
Disable Zeroconf Networking pass
Ensure System is Not Acting as a Network Sniffer pass
Disable Kernel Parameter for Sending ICMP Redirects by Default pass
Disable Kernel Parameter for Sending ICMP Redirects for All Interfaces pass
Disable Kernel Parameter for IP Forwarding pass
Disable Kernel Parameter for Accepting Source-Routed Packets for All Interfaces pass
Disable Kernel Parameter for Accepting ICMP Redirects for All Interfaces pass
Disable Kernel Parameter for Accepting Secure Redirects for All Interfaces pass
Enable Kernel Parameter to Log Martian Packets pass
Disable Kernel Parameter for Accepting Source-Routed Packets By Default pass
Disable Kernel Parameter for Accepting ICMP Redirects By Default pass
Disable Kernel Parameter for Accepting Secure Redirects By Default pass
Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests pass
Enable Kernel Parameter to Ignore Bogus ICMP Error Responses pass
Enable Kernel Parameter to Use TCP Syncookies pass
Enable Kernel Parameter to Use Reverse Path Filtering for All Interfaces pass
Enable Kernel Parameter to Use Reverse Path Filtering by Default pass
Disable WiFi or Bluetooth BIOS notchecked
Deactivate Wireless Network Interfaces pass
Disable Bluetooth Service pass
Disable Bluetooth Kernel Modules pass
Disable IPv6 Networking Support Automatic Loading pass
Disable Support for RPC IPv6 pass
Verify iptables Enabled pass
Set Default iptables Policy for Incoming Packets pass
Set Default iptables Policy for Forwarded Packets notchecked
Disable DCCP Support pass
Disable SCTP Support pass
Disable RDS Support pass
Disable TIPC Support pass
Ensure rsyslog is Installed pass
Enable rsyslog Service pass
Ensure Log Files Are Owned By Appropriate Group unknown
Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server pass
Enable rsyslog to Accept Messages via TCP, if Acting As Log Server notchecked
Enable rsyslog to Accept Messages via UDP, if Acting As Log Server notchecked
Ensure Logrotate Runs Periodically pass
Enable auditd Service pass
Enable Auditing for Processes Which Start Prior to the Audit Daemon pass
Configure auditd Number of Logs Retained pass
Configure auditd Max Log File Size pass
Configure auditd max_log_file_action Upon Reaching Maximum Log Size pass
Configure auditd space_left Action on Low Disk Space pass
Configure auditd admin_space_left Action on Low Disk Space pass
Configure auditd mail_acct Action on Low Disk Space pass
Configure auditd to use audispd plugin notchecked
Record attempts to alter time through adjtimex pass
Record attempts to alter time through settimeofday pass
Record Attempts to Alter Time Through stime pass
Record Attempts to Alter Time Through clock_settime pass
Record Attempts to Alter the localtime File pass
Record Events that Modify User/Group Information pass
Record Events that Modify the System's Network Environment pass
System Audit Logs Must Have Mode 0640 or Less Permissive pass
System Audit Logs Must Be Owned By Root pass
Record Events that Modify the System's Mandatory Access Controls pass
Record Events that Modify the System's Discretionary Access Controls - chmod pass
Record Events that Modify the System's Discretionary Access Controls - chown pass
Record Events that Modify the System's Discretionary Access Controls - fchmod pass
Record Events that Modify the System's Discretionary Access Controls - fchmodat pass
Record Events that Modify the System's Discretionary Access Controls - fchown pass
Record Events that Modify the System's Discretionary Access Controls - fchownat pass
Record Events that Modify the System's Discretionary Access Controls - fremovexattr pass
Record Events that Modify the System's Discretionary Access Controls - fsetxattr pass
Record Events that Modify the System's Discretionary Access Controls - lchown pass
Record Events that Modify the System's Discretionary Access Controls - lremovexattr pass
Record Events that Modify the System's Discretionary Access Controls - lsetxattr pass
Record Events that Modify the System's Discretionary Access Controls - removexattr pass
Record Events that Modify the System's Discretionary Access Controls - setxattr pass
Record Attempts to Alter Logon and Logout Events pass
Record Attempts to Alter Process and Session Initiation Information pass
Ensure auditd Collects Information on the Use of Privileged Commands notchecked
Ensure auditd Collects Information on Exporting to Media (successful) pass
Ensure auditd Collects System Administrator Actions pass
Ensure auditd Collects Information on Kernel Module Loading and Unloading pass
Make the auditd Configuration Immutable pass
Uninstall rsh-server Package pass
Disable rexec Service pass
Disable rsh Service pass
Disable rlogin Service pass
Uninstall ypserv Package pass
Disable ypbind Service pass
Disable tftp Service pass
Uninstall tftp-server Package pass
Ensure tftp Daemon Uses Secure Mode pass
Disable Automatic Bug Reporting Tool (abrtd) pass
Disable Advanced Configuration and Power Interface (acpid) pass
Disable Certmonger Service (certmonger) pass
Disable Control Group Config (cgconfig) pass
Disable CPU Speed (cpuspeed) pass
Disable Hardware Abstraction Layer Service (haldaemon) pass
Disable Software RAID Monitor (mdmonitor) pass
Disable D-Bus IPC Service (messagebus) pass
Disable Network Console (netconsole) pass
Disable ntpdate Service (ntpdate) pass
Disable Odd Job Daemon (oddjobd) pass
Disable Portreserve (portreserve) pass
Enable Process Accounting (psacct) pass
Disable Apache Qpid (qpidd) pass
Disable Quota Netlink (quota_nld) pass
Disable Network Router Discovery Daemon (rdisc) pass
Disable Red Hat Network Service (rhnsd) pass
Disable Red Hat Subscription Manager Daemon (rhsmcertd) pass
Disable Cyrus SASL Authentication Daemon (saslauthd) pass
Disable SMART Disk Monitoring Service (smartd) pass
Disable System Statistics Reset Service (sysstat) pass
Enable cron Service pass
Disable anacron Service notchecked
Disable At Service (atd) pass
Allow Only SSH Protocol 2 pass
Disable SSH Root Login pass
Use Only Approved Ciphers pass
Disable X Windows Startup By Setting Runlevel pass
Disable Avahi Server Software pass
Disable the CUPS Service pass
Disable Print Server Capabilities pass
Disable DHCP Service pass
Uninstall DHCP Server Package pass
Do Not Use Dynamic DNS notchecked
Deny Decline Messages notchecked
Deny BOOTP Queries notchecked
Disable DHCP Client pass
Enable the NTP Daemon pass
Specify a Remote NTP Server pass
Specify Additional Remote NTP Servers notchecked
Uninstall Sendmail Package pass
Disable Postfix Network Listening pass
Configure LDAP Client to Use TLS For All Transactions pass
Configure Certificate Directives for LDAP Use of TLS pass
Uninstall openldap-servers Package pass
Disable DNS Server pass
Uninstall bind Package pass
Authenticate Zone Transfers notchecked
Disable vsftpd Service pass
Uninstall vsftpd Package pass
Set httpd ServerTokens Directive to Prod notchecked
Set Permissions on the /var/log/httpd/ Directory pass
Set Permissions on All Configuration Files Inside /etc/httpd/conf/ pass

Results details

Result for Ensure /var/log/audit Located On Separate Partition

Result: pass

Rule ID: partition_for_var_log_audit

Time: 2014-07-16 17:32

Severity: low

Audit logs are stored in the /var/log/audit directory. Ensure that it has its own partition or logical volume at installation time, or migrate it later using LVM. Make absolutely certain that it is large enough to store all audit logs that will be created by the auditing daemon.

Placing /var/log/audit in its own partition enables better separation between audit files and other files, and helps ensure that auditing cannot be halted due to the partition running out of space.

Security identifiers

  • CCE-26436-6

Result for Install AIDE

Result: pass

Rule ID: package_aide_installed

Time: 2014-07-16 17:32

Severity: medium

Install the AIDE package with the command:

# yum install aide

The AIDE package must be installed if it is to be available for integrity checking.

Security identifiers

  • CCE-27024-9

Remediation script

                yum -y install aide

              

Result for Disable Prelinking

Result: pass

Rule ID: disable_prelink

Time: 2014-07-16 17:32

Severity: low

The prelinking feature changes binaries in an attempt to decrease their startup time. In order to disable it, change or add the following line inside the file /etc/sysconfig/prelink:

PRELINKING=no
Next, run the following command to return binaries to a normal, non-prelinked state:
# /usr/sbin/prelink -ua

The prelinking feature can interfere with the operation of AIDE, because it changes binaries.

Security identifiers

  • CCE-27221-1

Remediation script

                #
# Disable prelinking altogether
#
if grep -q ^PRELINKING /etc/sysconfig/prelink
then
  sed -i 's/PRELINKING.*/PRELINKING=no/g' /etc/sysconfig/prelink
else
  echo -e "\n# Set PRELINKING=no per security requirements" >> /etc/sysconfig/prelink
  echo "PRELINKING=no" >> /etc/sysconfig/prelink
fi

#
# Undo previous prelink changes to binaries
#
/usr/sbin/prelink -ua

              

Result for Build and Test AIDE Database

Result: notchecked

Rule ID: aide_build_database

Time: 2014-07-16 17:32

Severity: low

Run the following command to generate a new database:

# /usr/sbin/aide --init
By default, the database will be written to the file /var/lib/aide/aide.db.new.gz. Storing the database, the configuration file /etc/aide.conf, and the binary /usr/sbin/aide (or hashes of these files), in a secure location (such as on read-only media) provides additional assurance about their integrity. The newly-generated database can be installed as follows:
# cp /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz
To initiate a manual check, run the following command:
# /usr/sbin/aide --check
If this check produces any unexpected output, investigate.

For AIDE to be effective, an initial database of "known-good" information about files must be captured and it should be able to be verified against the installed files.

Security identifiers

  • CCE-27135-3

Result for Configure Periodic Execution of AIDE

Result: notchecked

Rule ID: aide_periodic_cron_checking

Time: 2014-07-16 17:32

Severity: medium

To implement a daily execution of AIDE at 4:05am using cron, add the following line to /etc/crontab:

05 4 * * * root /usr/sbin/aide --check
AIDE can be executed periodically through other means; this is merely one example.

By default, AIDE does not install itself for periodic execution. Periodically running AIDE is necessary to reveal unexpected changes in installed files.

Security identifiers

  • CCE-27222-9

Result for Install Intrusion Detection Software

Result: notchecked

Rule ID: install_hids

Time: 2014-07-16 17:32

Severity: high

The base Red Hat platform already includes a sophisticated auditing system that can detect intruder activity, as well as SELinux, which provides host-based intrusion prevention capabilities by confining privileged programs and user sessions which may become compromised.

Host-based intrusion detection tools provide a system-level defense when an intruder gains access to a system or network.

Security identifiers

  • CCE-27409-2

Result for Install Virus Scanning Software

Result: notchecked

Rule ID: install_antivirus

Time: 2014-07-16 17:32

Severity: low

Install virus scanning software, which uses signatures to search for the presence of viruses on the filesystem. The McAfee uvscan virus scanning tool is provided for DoD systems. Ensure virus definition files are no older than 7 days, or their last release. Configure the virus scanning software to perform scans dynamically on all accessed files. If this is not possible, configure the system to scan all altered files on the system on a daily basis. If the system processes inbound SMTP mail, configure the virus scanner to scan all received mail.

Virus scanning software can be used to detect if a system has been compromised by computer viruses, as well as to limit their spread to other systems.

Security identifiers

  • CCE-27529-7

Result for Add nodev Option to Non-Root Local Partitions

Result: pass

Rule ID: mountopt_nodev_on_nonroot_partitions

Time: 2014-07-16 17:32

Severity: low

The nodev mount option prevents files from being interpreted as character or block devices. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of any non-root local partitions.

The nodev mount option prevents files from being interpreted as character or block devices. The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails, for which it is not advised to set nodev on these filesystems.

Security identifiers

  • CCE-27045-4

Result for Add nodev Option to /tmp

Result: pass

Rule ID: mount_option_tmp_nodev

Time: 2014-07-16 17:32

Severity: low

The nodev mount option can be used to prevent device files from being created in /tmp. Legitimate character and block devices should not exist within temporary directories like /tmp. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Security identifiers

  • CCE-26499-4

Result for Add noexec Option to /tmp

Result: pass

Rule ID: mount_option_tmp_noexec

Time: 2014-07-16 17:32

Severity: low

The noexec mount option can be used to prevent binaries from being executed out of /tmp. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

Allowing users to execute binaries from world-writable directories such as /tmp should never be necessary in normal operation and can expose the system to potential compromise.

Security identifiers

  • CCE-26720-3

Result for Add nosuid Option to /tmp

Result: pass

Rule ID: mount_option_tmp_nosuid

Time: 2014-07-16 17:32

Severity: low

The nosuid mount option can be used to prevent execution of setuid programs in /tmp. The suid/sgid permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

The presence of suid and sgid executables should be tightly controlled. Users should not be able to execute suid or sgid binaries from temporary storage partitions.

Security identifiers

  • CCE-26762-5

Result for Add nodev Option to /dev/shm

Result: pass

Rule ID: mount_option_dev_shm_nodev

Time: 2014-07-16 17:32

Severity: low

The nodev mount option can be used to prevent creation of device files in /dev/shm. Legitimate character and block devices should not exist within temporary directories like /dev/shm. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Security identifiers

  • CCE-26778-1

Result for Add noexec Option to /dev/shm

Result: pass

Rule ID: mount_option_dev_shm_noexec

Time: 2014-07-16 17:32

Severity: low

The noexec mount option can be used to prevent binaries from being executed out of /dev/shm. It can be dangerous to allow the execution of binaries from world-writable temporary storage directories such as /dev/shm. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

Allowing users to execute binaries from world-writable directories such as /dev/shm can expose the system to potential compromise.

Security identifiers

  • CCE-26622-1

Result for Add nosuid Option to /dev/shm

Result: pass

Rule ID: mount_option_dev_shm_nosuid

Time: 2014-07-16 17:32

Severity: low

The nosuid mount option can be used to prevent execution of setuid programs in /dev/shm. The suid/sgid permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

The presence of suid and sgid executables should be tightly controlled. Users should not be able to execute suid or sgid binaries from temporary storage partitions.

Security identifiers

  • CCE-26486-1

Result for Disable Modprobe Loading of USB Storage Driver

Result: pass

Rule ID: kernel_module_usb-storage_disabled

Time: 2014-07-16 17:32

Severity: low

To prevent USB storage devices from being used, configure the kernel module loading system to prevent automatic loading of the USB storage driver. To configure the system to prevent the usb-storage kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install usb-storage /bin/false
This will prevent the modprobe program from loading the usb-storage module, but will not prevent an administrator (or another program) from using the insmod program to load the module manually.

USB storage devices such as thumb drives can be used to introduce malicious software.

Security identifiers

  • CCE-27016-5

Remediation script

                echo "install usb-storage /bin/false" > /etc/modprobe.d/usb-storage.conf

              

Result for Disable Booting from USB Devices in Boot Firmware

Result: notchecked

Rule ID: bios_disable_usb_boot

Time: 2014-07-16 17:32

Severity: low

Configure the system boot firmware (historically called BIOS on PC systems) to disallow booting from USB drives.

Booting a system from a USB device would allow an attacker to circumvent any security measures provided by the operating system. Attackers could mount partitions and modify the configuration of the OS.

Security identifiers

  • CCE-26923-3

Result for Disable the Automounter

Result: pass

Rule ID: service_autofs_disabled

Time: 2014-07-16 17:32

Severity: low

The autofs daemon mounts and unmounts filesystems, such as user home directories shared via NFS, on demand. In addition, autofs can be used to handle removable media, and the default configuration provides the cdrom device as /misc/cd. However, this method of providing access to removable media is not common, so autofs can almost always be disabled if NFS is not in use. Even if NFS is required, it may be possible to configure filesystem mounts statically by editing /etc/fstab rather than relying on the automounter.

The autofs service can be disabled with the following command:

# chkconfig autofs off

Disabling the automounter permits the administrator to statically control filesystem mounting through /etc/fstab.

Security identifiers

  • CCE-26976-1

Remediation script

                #
# Disable autofs for all run levels
#
chkconfig --level 0123456 autofs off

#
# Stop autofs if currently running
#
service autofs stop

              

Result for Disable GNOME Automounting

Result: pass

Rule ID: gconf_gnome_disable_automount

Time: 2014-07-16 17:32

Severity: low

The system's default desktop environment, GNOME, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. Disable automount and autorun within GNOME by running the following:

# gconftool-2 --direct \
	--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
	--type bool \
	--set /apps/nautilus/preferences/media_automount false
# gconftool-2 --direct \
	--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
	--type bool \
	--set /apps/nautilus/preferences/media_autorun_never true

Disabling automatic mounting in GNOME can prevent the introduction of malware via removable media. It will, however, also prevent desktop users from legitimate use of removable media.

Security identifiers

  • CCE-27035-5

Result for Disable Mounting of cramfs

Result: pass

Rule ID: kernel_module_cramfs_disabled

Time: 2014-07-16 17:32

Severity: low

To configure the system to prevent the cramfs kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install cramfs /bin/false
This effectively prevents usage of this uncommon filesystem.

Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.

Security identifiers

  • CCE-26340-0

Remediation script

                echo "install cramfs /bin/false" > /etc/modprobe.d/cramfs.conf

              

Result for Disable Mounting of freevxfs

Result: pass

Rule ID: kernel_module_freevxfs_disabled

Time: 2014-07-16 17:32

Severity: low

To configure the system to prevent the freevxfs kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install freevxfs /bin/false
This effectively prevents usage of this uncommon filesystem.

Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.

Security identifiers

  • CCE-26544-7

Remediation script

                echo "install freevxfs /bin/false" > /etc/modprobe.d/freevxfs.conf

              

Result for Disable Mounting of jffs2

Result: pass

Rule ID: kernel_module_jffs2_disabled

Time: 2014-07-16 17:32

Severity: low

To configure the system to prevent the jffs2 kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install jffs2 /bin/false
This effectively prevents usage of this uncommon filesystem.

Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.

Security identifiers

  • CCE-26670-0

Remediation script

                echo "install jffs2 /bin/false" > /etc/modprobe.d/jffs2.conf

              

Result for Disable Mounting of hfs

Result: pass

Rule ID: kernel_module_hfs_disabled

Time: 2014-07-16 17:32

Severity: low

To configure the system to prevent the hfs kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install hfs /bin/false
This effectively prevents usage of this uncommon filesystem.

Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.

Security identifiers

  • CCE-26800-3

Remediation script

                echo "install hfs /bin/false" > /etc/modprobe.d/hfs.conf

              

Result for Disable Mounting of hfsplus

Result: pass

Rule ID: kernel_module_hfsplus_disabled

Time: 2014-07-16 17:32

Severity: low

To configure the system to prevent the hfsplus kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install hfsplus /bin/false
This effectively prevents usage of this uncommon filesystem.

Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.

Security identifiers

  • CCE-26361-6

Remediation script

                echo "install hfsplus /bin/false" > /etc/modprobe.d/hfsplus.conf

              

Result for Disable Mounting of squashfs

Result: pass

Rule ID: kernel_module_squashfs_disabled

Time: 2014-07-16 17:32

Severity: low

To configure the system to prevent the squashfs kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install squashfs /bin/false
This effectively prevents usage of this uncommon filesystem.

Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.

Security identifiers

  • CCE-26404-4

Remediation script

                echo "install squashfs /bin/false" > /etc/modprobe.d/squashfs.conf

              

Result for Disable All GNOME Thumbnailers

Result: pass

Rule ID: disable_gnome_thumbnailers

Time: 2014-07-16 17:32

Severity: low

The system's default desktop environment, GNOME, uses a number of different thumbnailer programs to generate thumbnails for any new or modified content in an opened folder. The following command can disable the execution of these thumbnail applications:

# gconftool-2 --direct \
  --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
  --type bool \
  --set /desktop/gnome/thumbnailers/disable_all true
This effectively prevents an attacker from gaining access to a system through a flaw in GNOME's Nautilus thumbnail creators.

An attacker with knowledge of a flaw in a GNOME thumbnailer application could craft a malicious file to exploit this flaw. Assuming the attacker could place the malicious file on the local filesystem (via a web upload for example) and assuming a user browses the same location using Nautilus, the malicious file would exploit the thumbnailer with the potential for malicious code execution. It is best to disable these thumbnailer applications unless they are explicitly required.

Security identifiers

  • CCE-27224-5

Result for Verify User Who Owns shadow File

Result: pass

Rule ID: userowner_shadow_file

Time: 2014-07-16 17:32

Severity: medium

To properly set the owner of /etc/shadow, run the command:

# chown root /etc/shadow 

The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.

Security identifiers

  • CCE-26947-2

Remediation script

                chown root /etc/shadow

              

Result for Verify Group Who Owns shadow File

Result: pass

Rule ID: groupowner_shadow_file

Time: 2014-07-16 17:32

Severity: medium

To properly set the group owner of /etc/shadow, run the command:

# chgrp root /etc/shadow 

The /etc/shadow file stores password hashes. Protection of this file is critical for system security.

Security identifiers

  • CCE-26967-0

Remediation script

                chgrp root /etc/shadow

              

Result for Verify Permissions on shadow File

Result: pass

Rule ID: file_permissions_etc_shadow

Time: 2014-07-16 17:32

Severity: medium

To properly set the permissions of /etc/shadow, run the command:

# chmod 0000 /etc/shadow

The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.

Security identifiers

  • CCE-26992-8

Remediation script

                chmod 0000 /etc/shadow

              

Result for Verify User Who Owns group File

Result: pass

Rule ID: file_owner_etc_group

Time: 2014-07-16 17:32

Severity: medium

To properly set the owner of /etc/group, run the command:

# chown root /etc/group 

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Security identifiers

  • CCE-26822-7

Result for Verify Group Who Owns group File

Result: pass

Rule ID: file_groupowner_etc_group

Time: 2014-07-16 17:32

Severity: medium

To properly set the group owner of /etc/group, run the command:

# chgrp root /etc/group 

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Security identifiers

  • CCE-26930-8

Result for Verify Permissions on group File

Result: pass

Rule ID: file_permissions_etc_group

Time: 2014-07-16 17:32

Severity: medium

To properly set the permissions of /etc/group, run the command:

# chmod 644 /etc/group

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Security identifiers

  • CCE-26954-8

Result for Verify User Who Owns gshadow File

Result: pass

Rule ID: file_owner_etc_gshadow

Time: 2014-07-16 17:32

Severity: medium

To properly set the owner of /etc/gshadow, run the command:

# chown root /etc/gshadow 

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Security identifiers

  • CCE-27026-4

Result for Verify Group Who Owns gshadow File

Result: pass

Rule ID: file_groupowner_etc_gshadow

Time: 2014-07-16 17:32

Severity: medium

To properly set the group owner of /etc/gshadow, run the command:

# chgrp root /etc/gshadow 

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Security identifiers

  • CCE-26975-3

Result for Verify Permissions on gshadow File

Result: pass

Rule ID: file_permissions_etc_gshadow

Time: 2014-07-16 17:32

Severity: medium

To properly set the permissions of /etc/gshadow, run the command:

# chmod 0000 /etc/gshadow

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Security identifiers

  • CCE-26951-4

Result for Verify User Who Owns passwd File

Result: pass

Rule ID: file_owner_etc_passwd

Time: 2014-07-16 17:32

Severity: medium

To properly set the owner of /etc/passwd, run the command:

# chown root /etc/passwd 

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Security identifiers

  • CCE-26953-0

Result for Verify Group Who Owns passwd File

Result: pass

Rule ID: file_groupowner_etc_passwd

Time: 2014-07-16 17:32

Severity: medium

To properly set the group owner of /etc/passwd, run the command:

# chgrp root /etc/passwd 

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Security identifiers

  • CCE-26856-5

Result for Verify Permissions on passwd File

Result: pass

Rule ID: file_permissions_etc_passwd

Time: 2014-07-16 17:32

Severity: medium

To properly set the permissions of /etc/passwd, run the command:

# chmod 0644 /etc/passwd

If the /etc/passwd file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.

Security identifiers

  • CCE-26868-0

Result for Verify that Shared Library Files Have Restrictive Permissions

Result: pass

Rule ID: file_permissions_library_dirs

Time: 2014-07-16 17:32

Severity: medium

System-wide shared library files, which are linked to executables during process load time or run time, are stored in the following directories by default:

/lib
/lib64
/usr/lib
/usr/lib64
Kernel modules, which can be added to the kernel during runtime, are stored in /lib/modules. All files in these directories should not be group-writable or world-writable. If any file in these directories is found to be group-writable or world-writable, correct its permission with the following command:
# chmod go-w FILE

Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Restrictive permissions are necessary to protect the integrity of the system.

Security identifiers

  • CCE-27381-3

Remediation script

                DIRS="/lib /lib64 /usr/lib /usr/lib64"
for dirPath in $DIRS; do
	find $dirPath -perm /022 -type f -exec chmod go-w '{}' \;
done

              

Result for Verify that Shared Library Files Have Root Ownership

Result: pass

Rule ID: file_ownership_library_dirs

Time: 2014-07-16 17:32

Severity: medium

System-wide shared library files, which are linked to executables during process load time or run time, are stored in the following directories by default:

/lib
/lib64
/usr/lib
/usr/lib64
Kernel modules, which can be added to the kernel during runtime, are also stored in /lib/modules. All files in these directories should be owned by the root user. If the directory, or any file in these directories, is found to be owned by a user other than root correct its ownership with the following command:
# chown root FILE

Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Proper ownership is necessary to protect the integrity of the system.

Security identifiers

  • CCE-27424-1

Remediation script

                for LIBDIR in /usr/lib /usr/lib64 /lib /lib64
do
  if [ -d $LIBDIR ]
  then
    find -L $LIBDIR \! -user root -exec chown root {} \; 
  fi
done

              

Result for Verify that System Executables Have Restrictive Permissions

Result: pass

Rule ID: file_permissions_binary_dirs

Time: 2014-07-16 17:32

Severity: medium

System executables are stored in the following directories by default:

/bin
/usr/bin
/usr/local/bin
/sbin
/usr/sbin
/usr/local/sbin
All files in these directories should not be group-writable or world-writable. If any file FILE in these directories is found to be group-writable or world-writable, correct its permission with the following command:
# chmod go-w FILE

System binaries are executed by privileged users, as well as system services, and restrictive permissions are necessary to ensure execution of these programs cannot be co-opted.

Security identifiers

  • CCE-27289-8

Remediation script

                DIRS="/bin /usr/bin /usr/local/bin /sbin /usr/sbin /usr/local/sbin"
for dirPath in $DIRS; do
	find $dirPath -perm /022 -exec chmod go-w '{}' \;
done

              

Result for Verify that System Executables Have Root Ownership

Result: pass

Rule ID: file_ownership_binary_dirs

Time: 2014-07-16 17:32

Severity: medium

System executables are stored in the following directories by default:

/bin
/usr/bin
/usr/local/bin
/sbin
/usr/sbin
/usr/local/sbin
All files in these directories should be owned by the root user. If any file FILE in these directories is found to be owned by a user other than root, correct its ownership with the following command:
# chown root FILE

System binaries are executed by privileged users as well as system services, and restrictive permissions are necessary to ensure that their execution of these programs cannot be co-opted.

Security identifiers

  • CCE-27623-8

Result for Ensure All SGID Executables Are Authorized

Result: pass

Rule ID: no_unpackaged_sgid_files

Time: 2014-07-16 17:33

Severity: low

The SGID (set group id) bit should be set only on files that were installed via authorized means. A straightforward means of identifying unauthorized SGID files is determine if any were not installed as part of an RPM package, which is cryptographically verified. Investigate the origin of any unpackaged SGID files.

Executable files with the SGID permission run with the privileges of the owner of the file. SGID files of uncertain provenance could allow for unprivileged users to elevate privileges. The presence of these files should be strictly controlled on the system.

Security identifiers

  • CCE-26769-0

Result for Set Daemon Umask

Result: pass

Rule ID: umask_for_daemons

Time: 2014-07-16 17:33

Severity: low

The file /etc/init.d/functions includes initialization parameters for most or all daemons started at boot time. The default umask of 022 prevents creation of group- or world-writable files. To set the default umask for daemons, edit the following line, inserting 022 or 027 for UMASK appropriately:

umask UMASK
Setting the umask to too restrictive a setting can cause serious errors at runtime. Many daemons on the system already individually restrict themselves to a umask of 077 in their own init scripts.

The umask influences the permissions assigned to files created by a process at run time. An unnecessarily permissive umask could result in files being created with insecure permissions.

Security identifiers

  • CCE-27031-4

Remediation script

                var_umask_for_daemons="022"
grep -q ^umask /etc/init.d/functions && \
  sed -i "s/umask.*/umask $var_umask_for_daemons/g" /etc/init.d/functions
if ! [ $? -eq 0 ]; then
    echo "umask $var_umask_for_daemons" >> /etc/init.d/functions
fi

              

Result for Disable Core Dumps for All Users

Result: pass

Rule ID: disable_users_coredumps

Time: 2014-07-16 17:33

Severity: low

To disable core dumps for all users, add the following line to /etc/security/limits.conf:

*     hard   core    0

A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.

Security identifiers

  • CCE-27033-0

Remediation script

                echo "*     hard   core    0" >> /etc/security/limits.conf

              

Result for Disable Core Dumps for SUID programs

Result: pass

Rule ID: sysctl_fs_suid_dumpable

Time: 2014-07-16 17:33

Severity: low

To set the runtime status of the fs.suid_dumpable kernel parameter, run the following command:

# sysctl -w fs.suid_dumpable=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
fs.suid_dumpable = 0

The core dump of a setuid program is more likely to contain sensitive data, as the program itself runs with greater privileges than the user who initiated execution of the program. Disabling the ability for any setuid program to write a core file decreases the risk of unauthorized access of such data.

Security identifiers

  • CCE-27044-7

Remediation script

                #
# Set runtime for fs.suid_dumpable
#
sysctl -q -n -w fs.suid_dumpable=0

#
# If fs.suid_dumpable present in /etc/sysctl.conf, change value to "0"
#	else, add "fs.suid_dumpable = 0" to /etc/sysctl.conf
#
if grep --silent ^fs.suid_dumpable /etc/sysctl.conf ; then
	sed -i 's/^fs.suid_dumpable.*/fs.suid_dumpable = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set fs.suid_dumpable to 0 per security requirements" >> /etc/sysctl.conf
	echo "fs.suid_dumpable = 0" >> /etc/sysctl.conf
fi

              

Result for Enable Randomized Layout of Virtual Address Space

Result: pass

Rule ID: sysctl_kernel_randomize_va_space

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command:

# sysctl -w kernel.randomize_va_space=2
If this is not the system's default value, add the following line to /etc/sysctl.conf:
kernel.randomize_va_space = 2

Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.

Security identifiers

  • CCE-26999-3

Remediation script

                #
# Set runtime for kernel.randomize_va_space
#
sysctl -q -n -w kernel.randomize_va_space=2

#
# If kernel.randomize_va_space present in /etc/sysctl.conf, change value to "2"
#	else, add "kernel.randomize_va_space = 2" to /etc/sysctl.conf
#
if grep --silent ^kernel.randomize_va_space /etc/sysctl.conf ; then
	sed -i 's/^kernel.randomize_va_space.*/kernel.randomize_va_space = 2/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set kernel.randomize_va_space to 2 per security requirements" >> /etc/sysctl.conf
	echo "kernel.randomize_va_space = 2" >> /etc/sysctl.conf
fi

              

Result for Enable NX or XD Support in the BIOS

Result: notchecked

Rule ID: bios_enable_execution_restrictions

Time: 2014-07-16 17:33

Severity: low

Reboot the system and enter the BIOS or Setup configuration menu. Navigate the BIOS configuration menu and make sure that the option is enabled. The setting may be located under a Security section. Look for Execute Disable (XD) on Intel-based systems and No Execute (NX) on AMD-based systems.

Computers with the ability to prevent this type of code execution frequently put an option in the BIOS that will allow users to turn the feature on or off at will.

Security identifiers

  • CCE-27163-5

Result for Ensure SELinux Not Disabled in /etc/grub.conf

Result: pass

Rule ID: enable_selinux_bootloader

Time: 2014-07-16 17:33

Severity: medium

SELinux can be disabled at boot time by an argument in /etc/grub.conf. Remove any instances of selinux=0 from the kernel arguments in that file to prevent SELinux from being disabled at boot.

Disabling a major host protection feature, such as SELinux, at boot time prevents it from confining system services at boot time. Further, it increases the chances that it will remain off during system operation.

Security identifiers

  • CCE-26956-3

Remediation script

                sed -i "s/selinux=0//gI" /etc/grub.conf
sed -i "s/enforcing=0//gI" /etc/grub.conf

              

Result for Ensure SELinux State is Enforcing

Result: pass

Rule ID: selinux_state

Time: 2014-07-16 17:33

Severity: medium

The SELinux state should be set to enforcing at system boot time. In the file /etc/selinux/config, add or correct the following line to configure the system to boot into enforcing mode:

SELINUX=enforcing

Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.

Security identifiers

  • CCE-26969-6

Remediation script

                var_selinux_state="enforcing"
grep -q ^SELINUX= /etc/selinux/config && \
  sed -i "s/SELINUX=.*/SELINUX=$var_selinux_state/g" /etc/selinux/config
if ! [ $? -eq 0 ]; then
    echo "SELINUX=$var_selinux_state" >> /etc/selinux/config
fi

              

Result for Configure SELinux Policy

Result: pass

Rule ID: selinux_policytype

Time: 2014-07-16 17:33

Severity: low

The SELinux targeted policy is appropriate for general-purpose desktops and servers, as well as systems in many other roles. To configure the system to use this policy, add or correct the following line in /etc/selinux/config:

SELINUXTYPE=targeted
Other policies, such as mls, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases.

Setting the SELinux policy to targeted or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services.

Security identifiers

  • CCE-26875-5

Remediation script

                var_selinux_policy_name="mls"
grep -q ^SELINUXTYPE /etc/selinux/config && \
  sed -i "s/SELINUXTYPE=.*/SELINUXTYPE=$var_selinux_policy_name/g" /etc/selinux/config
if ! [ $? -eq 0 ]; then
    echo "SELINUXTYPE=$var_selinux_policy_name" >> /etc/selinux/config
fi

              

Result for Ensure No Daemons are Unconfined by SELinux

Result: notchecked

Rule ID: selinux_confinement_of_daemons

Time: 2014-07-16 17:33

Severity: medium

Daemons for which the SELinux policy does not contain rules will inherit the context of the parent process. Because daemons are launched during startup and descend from the init process, they inherit the initrc_t context.

To check for unconfined daemons, run the following command:

# ps -eZ | egrep "initrc" | egrep -vw "tr|ps|egrep|bash|awk" | tr ':' ' ' | awk '{ print $NF }'
It should produce no output in a well-configured system.

Daemons which run with the initrc_t context may cause AVC denials, or allow privileges that the daemon does not require.

Security identifiers

  • CCE-27111-4

Result for Direct root Logins Not Allowed

Result: notchecked

Rule ID: no_direct_root_logins

Time: 2014-07-16 17:33

Severity: medium

To further limit access to the root account, administrators can disable root logins at the console by editing the /etc/securetty file. This file lists all devices the root user is allowed to login to. If the file does not exist at all, the root user can login through any communication device on the system, whether via the console or via a raw network interface. This is dangerous as user can login to his machine as root via Telnet, which sends the password in plain text over the network. By default, Red Hat Enteprise Linux's /etc/securetty file only allows the root user to login at the console physically attached to the machine. To prevent root from logging in, remove the contents of this file. To prevent direct root logins, remove the contents of this file by typing the following command:


echo > /etc/securetty

Disabling direct root logins ensures proper accountability and multifactor authentication to privileged accounts. Users will first login, then escalate to privileged (root) access via su / sudo. This is required for FISMA Low and FISMA Moderate systems.

Security identifiers

  • CCE-26891-2

Result for Restrict Virtual Console Root Logins

Result: pass

Rule ID: securetty_root_login_console_only

Time: 2014-07-16 17:33

Severity: medium

To restrict root logins through the (deprecated) virtual console devices, ensure lines of this form do not appear in /etc/securetty:

vc/1
vc/2
vc/3
vc/4

Preventing direct root login to virtual console devices helps ensure accountability for actions taken on the system using the root account.

Security identifiers

  • CCE-26855-7

Remediation script

                sed -i '/^vc\//d' /etc/securetty

              

Result for Restrict Serial Port Root Logins

Result: pass

Rule ID: restrict_serial_port_logins

Time: 2014-07-16 17:33

Severity: low

To restrict root logins on serial ports, ensure lines of this form do not appear in /etc/securetty:

ttyS0
ttyS1

Preventing direct root login to serial port interfaces helps ensure accountability for actions taken on the systems using the root account.

Security identifiers

  • CCE-27047-0

Result for Verify Only Root Has UID 0

Result: pass

Rule ID: accounts_no_uid_except_zero

Time: 2014-07-16 17:33

Severity: medium

If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed.

An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.

Security identifiers

  • CCE-26971-2

Remediation script

                awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs passwd -l

              

Result for Prevent Log In to Accounts With Empty Password

Result: pass

Rule ID: no_empty_passwords

Time: 2014-07-16 17:33

Severity: high

If an account is configured for password authentication but does not have an assigned password, it may be possible to log into the account without authentication. Remove any instances of the nullok option in /etc/pam.d/system-auth to prevent logins with empty passwords.

If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.

Security identifiers

  • CCE-27038-9

Remediation script

                sed --follow-symlinks -i 's/\<nullok\>//g' /etc/pam.d/system-auth

              

Result for Verify All Account Password Hashes are Shadowed

Result: pass

Rule ID: accounts_password_all_shadowed

Time: 2014-07-16 17:33

Severity: medium

If any password hashes are stored in /etc/passwd (in the second field, instead of an x), the cause of this misconfiguration should be investigated. The account should have its password reset and the hash should be properly stored, or the account should be deleted entirely.

The hashes for all user account passwords should be stored in the file /etc/shadow and never in /etc/passwd, which is readable by all users.

Security identifiers

  • CCE-26476-2

Result for Verify No netrc Files Exist

Result: pass

Rule ID: no_netrc_files

Time: 2014-07-16 17:33

Severity: medium

The .netrc files contain login information used to auto-login into FTP servers and reside in the user's home directory. These files may contain unencrypted passwords to remote FTP servers making them susceptible to access by unauthorized users and should not be used. Any .netrc files should be removed.

Unencrypted passwords for remote FTP servers may be stored in .netrc files. DoD policy requires passwords be encrypted in storage and not used in access scripts.

Security identifiers

  • CCE-27225-2

Result for Set Password Minimum Length in login.defs

Result: pass

Rule ID: accounts_password_minlen_login_defs

Time: 2014-07-16 17:33

Severity: medium

To specify password length requirements for new accounts, edit the file /etc/login.defs and add or correct the following lines:

PASS_MIN_LEN 14


The DoD requirement is 14. The FISMA requirement is 12. If a program consults /etc/login.defs and also another PAM module (such as pam_cracklib) during a password change operation, then the most restrictive must be satisfied. See PAM section for more information about enforcing password quality requirements.

Requiring a minimum password length makes password cracking attacks more difficult by ensuring a larger search space. However, any security benefit from an onerous requirement must be carefully weighed against usability problems, support costs, or counterproductive behavior that may result.

Security identifiers

  • CCE-27002-5

Remediation script

                var_accounts_password_minlen_login_defs="12"
grep -q ^PASS_MIN_LEN /etc/login.defs && \
  sed -i "s/PASS_MIN_LEN.*/PASS_MIN_LEN     $var_accounts_password_minlen_login_defs/g" /etc/login.defs
if ! [ $? -eq 0 ]; then
    echo "PASS_MIN_LEN      $var_accounts_password_minlen_login_defs" >> /etc/login.defs
fi

              

Result for Set Password Maximum Age

Result: pass

Rule ID: accounts_maximum_age_login_defs

Time: 2014-07-16 17:33

Severity: medium

To specify password maximum age for new accounts, edit the file /etc/login.defs and add or correct the following line, replacing DAYS appropriately:

PASS_MAX_DAYS DAYS
A value of 180 days is sufficient for many environments. The DoD requirement is 60.

Setting the password maximum age ensures users are required to periodically change their passwords. This could possibly decrease the utility of a stolen password. Requiring shorter password lifetimes increases the risk of users writing down the password in a convenient location subject to physical compromise.

Security identifiers

  • CCE-26985-2

Remediation script

                var_accounts_maximum_age_login_defs="180"
grep -q ^PASS_MAX_DAYS /etc/login.defs && \
  sed -i "s/PASS_MAX_DAYS.*/PASS_MAX_DAYS     $var_accounts_maximum_age_login_defs/g" /etc/login.defs
if ! [ $? -eq 0 ]; then
    echo "PASS_MAX_DAYS      $var_accounts_maximum_age_login_defs" >> /etc/login.defs
fi

              

Result for Set Password Warning Age

Result: pass

Rule ID: accounts_password_warn_age_login_defs

Time: 2014-07-16 17:33

Severity: low

To specify how many days prior to password expiration that a warning will be issued to users, edit the file /etc/login.defs and add or correct the following line, replacing DAYS appropriately:

PASS_WARN_AGE DAYS
The DoD requirement is 7.

Setting the password warning age enables users to make the change at a practical time.

Security identifiers

  • CCE-26988-6

Remediation script

                var_accounts_password_warn_age_login_defs="7"
grep -q ^PASS_WARN_AGE /etc/login.defs && \
  sed -i "s/PASS_WARN_AGE.*/PASS_WARN_AGE     $var_accounts_password_warn_age_login_defs/g" /etc/login.defs
if ! [ $? -eq 0 ]; then
    echo "PASS_WARN_AGE      $var_accounts_password_warn_age_login_defs" >> /etc/login.defs
fi

              

Result for Set Account Expiration Following Inactivity

Result: pass

Rule ID: account_disable_post_pw_expiration

Time: 2014-07-16 17:33

Severity: low

To specify the number of days after a password expires (which signifies inactivity) until an account is permanently disabled, add or correct the following lines in /etc/default/useradd, substituting NUM_DAYS appropriately:

INACTIVE=NUM_DAYS
A value of 35 is recommended. If a password is currently on the verge of expiration, then 35 days remain until the account is automatically disabled. However, if the password will not expire for another 60 days, then 95 days could elapse until the account would be automatically disabled. See the useradd man page for more information. Determining the inactivity timeout must be done with careful consideration of the length of a "normal" period of inactivity for users in the particular environment. Setting the timeout too low incurs support costs and also has the potential to impact availability of the system to legitimate users.

Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials.

Security identifiers

  • CCE-27283-1

Remediation script

                var_account_disable_post_pw_expiration="35"
grep -q ^INACTIVE /etc/default/useradd && \
  sed -i "s/INACTIVE.*/INACTIVE=$var_account_disable_post_pw_expiration/g" /etc/default/useradd
if ! [ $? -eq 0 ]; then
    echo "INACTIVE=$var_account_disable_post_pw_expiration" >> /etc/default/useradd
fi

              

Result for Assign Expiration Date to Temporary Accounts

Result: notchecked

Rule ID: account_temp_expire_date

Time: 2014-07-16 17:33

Severity: low

In the event temporary or emergency accounts are required, configure the system to terminate them after a documented time period. For every temporary and emergency account, run the following command to set an expiration date on it, substituting USER and YYYY-MM-DD appropriately:

# chage -E YYYY-MM-DD USER
YYYY-MM-DD indicates the documented expiration date for the account.

When temporary and emergency accounts are created, there is a risk they may remain in place and active after the need for them no longer exists. Account expiration greatly reduces the risk of accounts being misused or hijacked.

Security identifiers

  • CCE-27474-6

Result for Set Password Retry Prompts Permitted Per-Session

Result: pass

Rule ID: accounts_password_pam_cracklib_retry

Time: 2014-07-16 17:33

Severity: low

To configure the number of retry prompts that are permitted per-session:

Edit the pam_cracklib.so statement in /etc/pam.d/system-auth to show retry=3, or a lower value if site policy is more restrictive.

The DoD requirement is a maximum of 3 prompts per session.

Setting the password retry prompts that are permitted on a per-session basis to a low value requires some software, such as SSH, to re-connect. This can slow down and draw additional attention to some types of password-guessing attacks. Note that this is different from account lockout, which is provided by the pam_faillock module.

Security identifiers

  • CCE-27123-9

Result for Set Password to Maximum of Three Consecutive Repeating Characters

Result: notchecked

Rule ID: password_require_consecrepeat

Time: 2014-07-16 17:33

Severity: low

The pam_cracklib module's maxrepeat parameter controls requirements for consecutive repeating characters. When set to a positive number, it will reject passwords which contain more than that number of consecutive characters. Add maxrepeat=3 after pam_cracklib.so to prevent a run of four or more identical characters.

Passwords with excessive repeating characters may be more vulnerable to password-guessing attacks.

Security identifiers

  • CCE-27227-8

Result for Set Password Strength Minimum Digit Characters

Result: pass

Rule ID: accounts_password_pam_cracklib_dcredit

Time: 2014-07-16 17:33

Severity: low

The pam_cracklib module's dcredit parameter controls requirements for usage of digits in a password. When set to a negative number, any password will be required to contain that many digits. When set to a positive number, pam_cracklib will grant +1 additional length credit for each digit. Add dcredit=-1 after pam_cracklib.so to require use of a digit in passwords.

Requiring digits makes password guessing attacks more difficult by ensuring a larger search space.

Security identifiers

  • CCE-26374-9

Result for Set Password Strength Minimum Uppercase Characters

Result: pass

Rule ID: accounts_password_pam_cracklib_ucredit

Time: 2014-07-16 17:33

Severity: low

The pam_cracklib module's ucredit= parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contain that many uppercase characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each uppercase character. Add ucredit=-1 after pam_cracklib.so to require use of an upper case character in passwords.

Requiring a minimum number of uppercase characters makes password guessing attacks more difficult by ensuring a larger search space.

Security identifiers

  • CCE-26601-5

Result for Set Password Strength Minimum Special Characters

Result: pass

Rule ID: accounts_password_pam_cracklib_ocredit

Time: 2014-07-16 17:33

Severity: low

The pam_cracklib module's ocredit= parameter controls requirements for usage of special (or ``other'') characters in a password. When set to a negative number, any password will be required to contain that many special characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each special character. Add ocredit=-1 after pam_cracklib.so to require use of a special character in passwords.

Requiring a minimum number of special characters makes password guessing attacks more difficult by ensuring a larger search space.

Security identifiers

  • CCE-26409-3

Result for Set Password Strength Minimum Lowercase Characters

Result: pass

Rule ID: accounts_password_pam_cracklib_lcredit

Time: 2014-07-16 17:33

Severity: low

The pam_cracklib module's lcredit= parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain that many lowercase characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each lowercase character. Add lcredit=-1 after pam_cracklib.so to require use of a lowercase character in passwords.

Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space.

Security identifiers

  • CCE-26631-2

Result for Set Password Strength Minimum Different Characters

Result: pass

Rule ID: accounts_password_pam_cracklib_difok

Time: 2014-07-16 17:33

Severity: low

The pam_cracklib module's difok parameter controls requirements for usage of different characters during a password change. Add difok=NUM after pam_cracklib.so to require differing characters when changing passwords, substituting NUM appropriately. The DoD requirement is 4.

Requiring a minimum number of different characters during password changes ensures that newly changed passwords should not resemble previously compromised ones. Note that passwords which are changed on compromised systems will still be compromised, however.

Security identifiers

  • CCE-26615-5

Result for Limit Password Reuse

Result: pass

Rule ID: accounts_password_reuse_limit

Time: 2014-07-16 17:33

Severity: medium

Do not allow users to reuse recent passwords. This can be accomplished by using the remember option for the pam_unix PAM module. In the file /etc/pam.d/system-auth, append remember=24 to the line which refers to the pam_unix.so module, as shown:

password sufficient pam_unix.so existing_options remember=24
The DoD and FISMA requirement is 24 passwords.

Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.

Security identifiers

  • CCE-26741-9

Result for Set Password Hashing Algorithm in /etc/login.defs

Result: pass

Rule ID: set_password_hashing_algorithm_logindefs

Time: 2014-07-16 17:33

Severity: medium

In /etc/login.defs, add or correct the following line to ensure the system will use SHA-512 as the hashing algorithm:

ENCRYPT_METHOD SHA512

Using a stronger hashing algorithm makes password cracking attacks more difficult.

Security identifiers

  • CCE-27228-6

Result for Set Password Hashing Algorithm in /etc/libuser.conf

Result: pass

Rule ID: set_password_hashing_algorithm_libuserconf

Time: 2014-07-16 17:33

Severity: medium

In /etc/libuser.conf, add or correct the following line in its [defaults] section to ensure the system will use the SHA-512 algorithm for password hashing:

crypt_style = sha512

Using a stronger hashing algorithm makes password cracking attacks more difficult.

Security identifiers

  • CCE-27229-4

Result for Limit the Number of Concurrent Login Sessions Allowed Per User

Result: unknown

Rule ID: accounts_max_concurrent_login_sessions

Time: 2014-07-16 17:33

Severity: low

Limiting the number of allowed users and sessions per user can limit risks related to Denial of Service attacks. This addresses concurrent sessions for a single account and does not address concurrent sessions by a single user via multiple accounts. The DoD requirement is 10. To set the number of concurrent sessions per user add the following line in /etc/security/limits.conf:

* hard maxlogins 10

Limiting simultaneous user logins can insulate the system from denial of service problems caused by excessive logins. Automated login processes operating improperly or maliciously may result in an exceptional number of simultaneous login sessions.

Security identifiers

  • CCE-27457-1

Remediation script

var_accounts_max_concurrent_login_sessions="1"
echo "*	hard	maxlogins	$var_accounts_max_concurrent_login_sessions" >> /etc/security/limits.conf

Result for Set Boot Loader Password

Result: pass

Rule ID: bootloader_password

Time: 2014-07-16 17:33

Severity: medium

The grub boot loader should have password protection enabled to protect boot-time settings. To do so, select a password and then generate a hash from it by running the following command:

# grub-crypt --sha-512
When prompted to enter a password, insert the following line into /etc/grub.conf immediately after the header comments. (Use the output from grub-crypt as the value of password-hash):
password --encrypted password-hash
NOTE: To meet FISMA Moderate, the bootloader password MUST differ from the root password.

Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.

Security identifiers

  • CCE-26911-8

Result for Disable Interactive Boot

Result: pass

Rule ID: disable_interactive_boot

Time: 2014-07-16 17:33

Severity: medium

To disable the ability for users to perform interactive startups, edit the file /etc/sysconfig/init. Add or correct the line:

PROMPT=no
The PROMPT option allows the console user to perform an interactive system startup, in which it is possible to select the set of services which are started on boot.

Using interactive boot, the console user could disable auditing, firewalls, or other services, weakening system security.

Security identifiers

  • CCE-27043-9

Remediation script

                grep -q ^PROMPT /etc/sysconfig/init && \
  sed -i "s/PROMPT.*/PROMPT=no/g" /etc/sysconfig/init
if ! [ $? -eq 0 ]; then
    echo "PROMPT=no" >> /etc/sysconfig/init
fi

              

Result for GNOME Desktop Screensaver Mandatory Use

Result: pass

Rule ID: enable_screensaver_after_idle

Time: 2014-07-16 17:33

Severity: medium

Run the following command to activate the screensaver in the GNOME desktop after a period of inactivity:

# gconftool-2 --direct \
  --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
  --type bool \
  --set /apps/gnome-screensaver/idle_activation_enabled true

Enabling idle activation of the screen saver ensures the screensaver will be activated after the idle delay. Applications requiring continuous, real-time screen display (such as network management products) require the login session does not have administrator rights and the display station is located in a controlled-access area.

Security identifiers

  • CCE-26600-7

Result for Enable Screen Lock Activation After Idle Period

Result: pass

Rule ID: enable_screensaver_password_lock

Time: 2014-07-16 17:33

Severity: medium

Run the following command to activate locking of the screensaver in the GNOME desktop when it is activated:

# gconftool-2 --direct \
  --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
  --type bool \
  --set /apps/gnome-screensaver/lock_enabled true

Enabling the activation of the screen lock after an idle period ensures password entry will be required in order to access the system, preventing access by passersby.

Security identifiers

  • CCE-26235-2

Result for Implement Blank Screen Saver

Result: pass

Rule ID: set_blank_screensaver

Time: 2014-07-16 17:33

Severity: low

Run the following command to set the screensaver mode in the GNOME desktop to a blank screen:

# gconftool-2 --direct \
  --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
  --type string \
  --set /apps/gnome-screensaver/mode blank-only

Setting the screensaver mode to blank-only conceals the contents of the display from passersby.

Security identifiers

  • CCE-26638-7

Result for Set GUI Warning Banner Text

Result: notchecked

Rule ID: set_gdm_login_banner_text

Time: 2014-07-16 17:33

Severity: medium

To set the text shown by the GNOME Display Manager in the login screen, run the following command:

sudo -u gdm gconftool-2 \
  --type string \
  --set /apps/gdm/simple-greeter/banner_message_text \
  "Text of the warning banner here"
When entering a warning banner that spans several lines, remember to begin and end the string with ". This command writes directly to the file /var/lib/gdm/.gconf/apps/gdm/simple-greeter/%gconf.xml, and this file can later be edited directly if necessary.

An appropriate warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers.

Security identifiers

  • CCE-27017-3

Result for Disable Zeroconf Networking

Result: pass

Rule ID: network_disable_zeroconf

Time: 2014-07-16 17:33

Severity: low

Zeroconf networking allows the system to assign itself an IP address and engage in IP communication without a statically-assigned address or even a DHCP server. Automatic address assignment via Zeroconf (or DHCP) is not recommended. To disable Zeroconf automatic route assignment in the 169.254.0.0 subnet, add or correct the following line in /etc/sysconfig/network:

NOZEROCONF=yes

Zeroconf addresses are in the network 169.254.0.0. The networking scripts add entries to the system's routing table for these addresses. Zeroconf address assignment commonly occurs when the system is configured to use DHCP but fails to receive an address assignment from the DHCP server.

Security identifiers

  • CCE-27151-0

Remediation script

                echo "NOZEROCONF=yes" >> /etc/sysconfig/network

              

Result for Ensure System is Not Acting as a Network Sniffer

Result: pass

Rule ID: network_sniffer_disabled

Time: 2014-07-16 17:33

Severity: low

The system should not be acting as a network sniffer, which can capture all traffic on the network to which it is connected. Run the following to determine if any interface is running in promiscuous mode:

$ ip link | grep PROMISC

If any results are returned, then a sniffing process (such as tcpdump or Wireshark) is likely to be using the interface and this should be investigated.

Security identifiers

  • CCE-27152-8

Result for Disable Kernel Parameter for Sending ICMP Redirects by Default

Result: pass

Rule ID: sysctl_net_ipv4_conf_default_send_redirects

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.default.send_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.default.send_redirects = 0

Sending ICMP redirects permits the system to instruct other systems to update their routing information. The ability to send ICMP redirects is only appropriate for systems acting as routers.

Security identifiers

  • CCE-27001-7

Remediation script

                #
# Set runtime for net.ipv4.conf.default.send_redirects
#
sysctl -q -n -w net.ipv4.conf.default.send_redirects=0

#
# If net.ipv4.conf.default.send_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.default.send_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.send_redirects /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.default.send_redirects.*/net.ipv4.conf.default.send_redirects = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.default.send_redirects to 0 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.default.send_redirects = 0" >> /etc/sysctl.conf
fi

              

Result for Disable Kernel Parameter for Sending ICMP Redirects for All Interfaces

Result: pass

Rule ID: sysctl_ipv4_all_send_redirects

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.all.send_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.all.send_redirects = 0

Sending ICMP redirects permits the system to instruct other systems to update their routing information. The ability to send ICMP redirects is only appropriate for systems acting as routers.

Security identifiers

  • CCE-27004-1

Result for Disable Kernel Parameter for IP Forwarding

Result: pass

Rule ID: sysctl_ipv4_ip_forward

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.ip_forward kernel parameter, run the following command:

# sysctl -w net.ipv4.ip_forward=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.ip_forward = 0

IP forwarding permits the kernel to forward packets from one network interface to another. The ability to forward packets between two networks is only appropriate for systems acting as routers.

Security identifiers

  • CCE-26866-4

Result for Disable Kernel Parameter for Accepting Source-Routed Packets for All Interfaces

Result: pass

Rule ID: sysctl_net_ipv4_conf_all_accept_source_route

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.all.accept_source_route kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.all.accept_source_route=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.all.accept_source_route = 0

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Security identifiers

  • CCE-27037-1

Remediation script

                #
# Set runtime for net.ipv4.conf.all.accept_source_route
#
sysctl -q -n -w net.ipv4.conf.all.accept_source_route=0

#
# If net.ipv4.conf.all.accept_source_route present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.accept_source_route = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.accept_source_route /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.all.accept_source_route.*/net.ipv4.conf.all.accept_source_route = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.all.accept_source_route to 0 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.all.accept_source_route = 0" >> /etc/sysctl.conf
fi

              

Result for Disable Kernel Parameter for Accepting ICMP Redirects for All Interfaces

Result: pass

Rule ID: sysctl_net_ipv4_conf_all_accept_redirects

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.all.accept_redirects kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.all.accept_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.all.accept_redirects = 0

Accepting ICMP redirects has few legitimate uses. It should be disabled unless it is absolutely required.

Security identifiers

  • CCE-27027-2

Remediation script

                #
# Set runtime for net.ipv4.conf.all.accept_redirects
#
sysctl -q -n -w net.ipv4.conf.all.accept_redirects=0

#
# If net.ipv4.conf.all.accept_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.accept_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.accept_redirects /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.all.accept_redirects.*/net.ipv4.conf.all.accept_redirects = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.all.accept_redirects to 0 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.all.accept_redirects = 0" >> /etc/sysctl.conf
fi

              

Result for Disable Kernel Parameter for Accepting Secure Redirects for All Interfaces

Result: pass

Rule ID: sysctl_net_ipv4_conf_all_secure_redirects

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.all.secure_redirects kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.all.secure_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.all.secure_redirects = 0

Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.

Security identifiers

  • CCE-26854-0

Remediation script

                #
# Set runtime for net.ipv4.conf.all.secure_redirects
#
sysctl -q -n -w net.ipv4.conf.all.secure_redirects=0

#
# If net.ipv4.conf.all.secure_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.all.secure_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.secure_redirects /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.all.secure_redirects.*/net.ipv4.conf.all.secure_redirects = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.all.secure_redirects to 0 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.all.secure_redirects = 0" >> /etc/sysctl.conf
fi

              

Result for Enable Kernel Parameter to Log Martian Packets

Result: pass

Rule ID: sysctl_net_ipv4_conf_all_log_martians

Time: 2014-07-16 17:33

Severity: low

To set the runtime status of the net.ipv4.conf.all.log_martians kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.all.log_martians=1
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.all.log_martians = 1

The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.

Security identifiers

  • CCE-27066-0

Remediation script

                #
# Set runtime for net.ipv4.conf.all.log_martians
#
sysctl -q -n -w net.ipv4.conf.all.log_martians=1

#
# If net.ipv4.conf.all.log_martians present in /etc/sysctl.conf, change value to "1"
#	else, add "net.ipv4.conf.all.log_martians = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.log_martians /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.all.log_martians.*/net.ipv4.conf.all.log_martians = 1/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.all.log_martians to 1 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.all.log_martians = 1" >> /etc/sysctl.conf
fi

              

Result for Disable Kernel Parameter for Accepting Source-Routed Packets By Default

Result: pass

Rule ID: sysctl_net_ipv4_conf_default_accept_source_route

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.default.accept_source_route kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.default.accept_source_route=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.default.accept_source_route = 0

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Security identifiers

  • CCE-26983-7

Remediation script

                #
# Set runtime for net.ipv4.conf.default.accept_source_route
#
sysctl -q -n -w net.ipv4.conf.default.accept_source_route=0

#
# If net.ipv4.conf.default.accept_source_route present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.default.accept_source_route = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.accept_source_route /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.default.accept_source_route.*/net.ipv4.conf.default.accept_source_route = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.default.accept_source_route to 0 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.default.accept_source_route = 0" >> /etc/sysctl.conf
fi

              

Result for Disable Kernel Parameter for Accepting ICMP Redirects By Default

Result: pass

Rule ID: sysctl_net_ipv4_conf_default_accept_redirects

Time: 2014-07-16 17:33

Severity: low

To set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.default.accept_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.default.accept_redirects = 0

This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Security identifiers

  • CCE-27015-7

Remediation script

                #
# Set runtime for net.ipv4.conf.default.accept_redirects
#
sysctl -q -n -w net.ipv4.conf.default.accept_redirects=0

#
# If net.ipv4.conf.default.accept_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.default.accept_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.accept_redirects /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.default.accept_redirects.*/net.ipv4.conf.default.accept_redirects = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.default.accept_redirects to 0 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.default.accept_redirects = 0" >> /etc/sysctl.conf
fi

              

Result for Disable Kernel Parameter for Accepting Secure Redirects By Default

Result: pass

Rule ID: sysctl_net_ipv4_conf_default_secure_redirects

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.default.secure_redirects kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.default.secure_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.default.secure_redirects = 0

Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.

Security identifiers

  • CCE-26831-8

Remediation script

                #
# Set runtime for net.ipv4.conf.default.secure_redirects
#
sysctl -q -n -w net.ipv4.conf.default.secure_redirects=0

#
# If net.ipv4.conf.default.secure_redirects present in /etc/sysctl.conf, change value to "0"
#	else, add "net.ipv4.conf.default.secure_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.secure_redirects /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.default.secure_redirects.*/net.ipv4.conf.default.secure_redirects = 0/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.default.secure_redirects to 0 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.default.secure_redirects = 0" >> /etc/sysctl.conf
fi

              

Result for Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests

Result: pass

Rule ID: sysctl_net_ipv4_icmp_echo_ignore_broadcasts

Time: 2014-07-16 17:33

Severity: low

To set the runtime status of the net.ipv4.icmp_echo_ignore_broadcasts kernel parameter, run the following command:

# sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.icmp_echo_ignore_broadcasts = 1

Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.

Security identifiers

  • CCE-26883-9

Remediation script

                #
# Set runtime for net.ipv4.icmp_echo_ignore_broadcasts
#
sysctl -q -n -w net.ipv4.icmp_echo_ignore_broadcasts=1

#
# If net.ipv4.icmp_echo_ignore_broadcasts present in /etc/sysctl.conf, change value to "1"
#	else, add "net.ipv4.icmp_echo_ignore_broadcasts = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.icmp_echo_ignore_broadcasts /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.icmp_echo_ignore_broadcasts.*/net.ipv4.icmp_echo_ignore_broadcasts = 1/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.icmp_echo_ignore_broadcasts to 1 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.icmp_echo_ignore_broadcasts = 1" >> /etc/sysctl.conf
fi

              

Result for Enable Kernel Parameter to Ignore Bogus ICMP Error Responses

Result: pass

Rule ID: sysctl_net_ipv4_icmp_ignore_bogus_error_responses

Time: 2014-07-16 17:33

Severity: low

To set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter, run the following command:

# sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.icmp_ignore_bogus_error_responses = 1

Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.

Security identifiers

  • CCE-26993-6

Remediation script

                #
# Set runtime for net.ipv4.icmp_ignore_bogus_error_responses
#
sysctl -q -n -w net.ipv4.icmp_ignore_bogus_error_responses=1

#
# If net.ipv4.icmp_ignore_bogus_error_responses present in /etc/sysctl.conf, change value to "1"
#	else, add "net.ipv4.icmp_ignore_bogus_error_responses = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.icmp_ignore_bogus_error_responses /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.icmp_ignore_bogus_error_responses.*/net.ipv4.icmp_ignore_bogus_error_responses = 1/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.icmp_ignore_bogus_error_responses to 1 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.icmp_ignore_bogus_error_responses = 1" >> /etc/sysctl.conf
fi

              

Result for Enable Kernel Parameter to Use TCP Syncookies

Result: pass

Rule ID: sysctl_net_ipv4_tcp_syncookies

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command:

# sysctl -w net.ipv4.tcp_syncookies=1
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.tcp_syncookies = 1

A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.

Security identifiers

  • CCE-27053-8

Remediation script

                #
# Set runtime for net.ipv4.tcp_syncookies
#
sysctl -q -n -w net.ipv4.tcp_syncookies=1

#
# If net.ipv4.tcp_syncookies present in /etc/sysctl.conf, change value to "1"
#	else, add "net.ipv4.tcp_syncookies = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.tcp_syncookies /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.tcp_syncookies.*/net.ipv4.tcp_syncookies = 1/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.tcp_syncookies to 1 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.tcp_syncookies = 1" >> /etc/sysctl.conf
fi

              

Result for Enable Kernel Parameter to Use Reverse Path Filtering for All Interfaces

Result: pass

Rule ID: sysctl_net_ipv4_conf_all_rp_filter

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.all.rp_filter=1
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.all.rp_filter = 1

Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.

Security identifiers

  • CCE-26979-5

Remediation script

                #
# Set runtime for net.ipv4.conf.all.rp_filter
#
sysctl -q -n -w net.ipv4.conf.all.rp_filter=1

#
# If net.ipv4.conf.all.rp_filter present in /etc/sysctl.conf, change value to "1"
#	else, add "net.ipv4.conf.all.rp_filter = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.rp_filter /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.all.rp_filter.*/net.ipv4.conf.all.rp_filter = 1/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.all.rp_filter to 1 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.all.rp_filter = 1" >> /etc/sysctl.conf
fi

              

Result for Enable Kernel Parameter to Use Reverse Path Filtering by Default

Result: pass

Rule ID: sysctl_net_ipv4_conf_default_rp_filter

Time: 2014-07-16 17:33

Severity: medium

To set the runtime status of the net.ipv4.conf.default.rp_filter kernel parameter, run the following command:

# sysctl -w net.ipv4.conf.default.rp_filter=1
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv4.conf.default.rp_filter = 1

Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.

Security identifiers

  • CCE-26915-9

Remediation script

                #
# Set runtime for net.ipv4.conf.default.rp_filter
#
sysctl -q -n -w net.ipv4.conf.default.rp_filter=1

#
# If net.ipv4.conf.default.rp_filter present in /etc/sysctl.conf, change value to "1"
#	else, add "net.ipv4.conf.default.rp_filter = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.rp_filter /etc/sysctl.conf ; then
	sed -i 's/^net.ipv4.conf.default.rp_filter.*/net.ipv4.conf.default.rp_filter = 1/g' /etc/sysctl.conf
else
	echo "" >> /etc/sysctl.conf
	echo "# Set net.ipv4.conf.default.rp_filter to 1 per security requirements" >> /etc/sysctl.conf
	echo "net.ipv4.conf.default.rp_filter = 1" >> /etc/sysctl.conf
fi

              

Result for Disable WiFi or Bluetooth BIOS

Result: notchecked

Rule ID: wireless_disable_in_bios

Time: 2014-07-16 17:33

Severity: low

Some systems that include built-in wireless support offer the ability to disable the device through the BIOS. This is system-specific; consult your hardware manual or explore the BIOS setup during boot.

Disabling wireless support in the BIOS prevents easy activation of the wireless interface, generally requiring administrators to reboot the system first.

Security identifiers

  • CCE-26878-9

Result for Deactivate Wireless Network Interfaces

Result: pass

Rule ID: deactivate_wireless_interfaces

Time: 2014-07-16 17:33

Severity: low

Deactivating wireless network interfaces should prevent normal usage of the wireless capability.

First, identify the interfaces available with the command:

# ifconfig -a
Additionally,the following command may also be used to determine whether wireless support ('extensions') is included for a particular interface, though this may not always be a clear indicator:
# iwconfig
After identifying any wireless interfaces (which may have names like wlan0, ath0, wifi0, em1 or eth0), deactivate the interface with the command:
# ifdown interface
These changes will only last until the next reboot. To disable the interface for future boots, remove the appropriate interface file from /etc/sysconfig/network-scripts:
# rm /etc/sysconfig/network-scripts/ifcfg-interface

Wireless networking allows attackers within physical proximity to launch network-based attacks against systems, including those against local LAN protocols which were not designed with security in mind.

Security identifiers

  • CCE-27057-9

Result for Disable Bluetooth Service

Result: pass

Rule ID: service_bluetooth_disabled

Time: 2014-07-16 17:33

Severity: medium

The bluetooth service can be disabled with the following command:

# chkconfig bluetooth off
# service bluetooth stop

Disabling the bluetooth service prevents the system from attempting connections to Bluetooth devices, which entails some security risk. Nevertheless, variation in this risk decision may be expected due to the utility of Bluetooth connectivity and its limited range.

Security identifiers

  • CCE-27081-9

Remediation script

                #
# Disable bluetooth for all run levels
#
chkconfig --level 0123456 bluetooth off

#
# Stop bluetooth if currently running
#
service bluetooth stop

              

Result for Disable Bluetooth Kernel Modules

Result: pass

Rule ID: kernel_module_bluetooth_disabled

Time: 2014-07-16 17:33

Severity: medium

The kernel's module loading system can be configured to prevent loading of the Bluetooth module. Add the following to the appropriate /etc/modprobe.d configuration file to prevent the loading of the Bluetooth module:

install net-pf-31 /bin/false
install bluetooth /bin/false

If Bluetooth functionality must be disabled, preventing the kernel from loading the kernel module provides an additional safeguard against its activation.

Security identifiers

  • CCE-26763-3

Result for Disable IPv6 Networking Support Automatic Loading

Result: pass

Rule ID: kernel_module_ipv6_option_disabled

Time: 2014-07-16 17:33

Severity: medium

To prevent the IPv6 kernel module (ipv6) from loading the IPv6 networking stack, add the following line to /etc/modprobe.d/disabled.conf (or another file in /etc/modprobe.d):

options ipv6 disable=1
This permits the IPv6 module to be loaded (and thus satisfy other modules that depend on it), while disabling support for the IPv6 protocol.

Any unnecessary network stacks - including IPv6 - should be disabled, to reduce the vulnerability to exploitation.

Security identifiers

  • CCE-27153-6

Result for Disable Support for RPC IPv6

Result: pass

Rule ID: network_ipv6_disable_rpc

Time: 2014-07-16 17:33

Severity: low

RPC services for NFSv4 try to load transport modules for udp6 and tcp6 by default, even if IPv6 has been disabled in /etc/modprobe.d. To prevent RPC services such as rpc.mountd from attempting to start IPv6 network listeners, remove or comment out the following two lines in /etc/netconfig:

udp6       tpi_clts      v     inet6    udp     -       -
tcp6       tpi_cots_ord  v     inet6    tcp     -       -

Security identifiers

  • CCE-27232-8

Result for Verify iptables Enabled

Result: pass

Rule ID: service_iptables_enabled

Time: 2014-07-16 17:33

Severity: medium

The iptables service can be enabled with the following command:

# chkconfig --level 2345 iptables on

The iptables service provides the system's host-based firewalling capability for IPv4 and ICMP.

Security identifiers

  • CCE-27018-1

Remediation script

                #
# Enable iptables for all run levels
#
chkconfig --level 0123456 iptables on

#
# Start iptables if not currently running
#
service iptables start

              

Result for Set Default iptables Policy for Incoming Packets

Result: pass

Rule ID: set_iptables_default_rule

Time: 2014-07-16 17:33

Severity: medium

To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in /etc/sysconfig/iptables:

:INPUT DROP [0:0]

In iptables the default policy is applied only after all the applicable rules in the table are examined for a match. Setting the default policy to DROP implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.

Security identifiers

  • CCE-26444-0

Result for Set Default iptables Policy for Forwarded Packets

Result: notchecked

Rule ID: set_iptables_default_rule_forward

Time: 2014-07-16 17:33

Severity: medium

To set the default policy to DROP (instead of ACCEPT) for the built-in FORWARD chain which processes packets that will be forwarded from one interface to another, add or correct the following line in /etc/sysconfig/iptables:

:FORWARD DROP [0:0]

In iptables the default policy is applied only after all the applicable rules in the table are examined for a match. Setting the default policy to DROP implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.

Security identifiers

  • CCE-27186-6

Result for Disable DCCP Support

Result: pass

Rule ID: kernel_module_dccp_disabled

Time: 2014-07-16 17:33

Severity: medium

The Datagram Congestion Control Protocol (DCCP) is a relatively new transport layer protocol, designed to support streaming media and telephony. To configure the system to prevent the dccp kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install dccp /bin/false

Disabling DCCP protects the system against exploitation of any flaws in its implementation.

Security identifiers

  • CCE-26448-1

Remediation script

                echo "install dccp /bin/false" > /etc/modprobe.d/dccp.conf

              

Result for Disable SCTP Support

Result: pass

Rule ID: kernel_module_sctp_disabled

Time: 2014-07-16 17:33

Severity: medium

The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. To configure the system to prevent the sctp kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install sctp /bin/false

Disabling SCTP protects the system against exploitation of any flaws in its implementation.

Security identifiers

  • CCE-26410-1

Remediation script

                echo "install sctp /bin/false" > /etc/modprobe.d/sctp.conf

              

Result for Disable RDS Support

Result: pass

Rule ID: kernel_module_rds_disabled

Time: 2014-07-16 17:33

Severity: low

The Reliable Datagram Sockets (RDS) protocol is a transport layer protocol designed to provide reliable high- bandwidth, low-latency communications between nodes in a cluster. To configure the system to prevent the rds kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install rds /bin/false

Disabling RDS protects the system against exploitation of any flaws in its implementation.

Security identifiers

  • CCE-26239-4

Remediation script

                echo "install rds /bin/false" > /etc/modprobe.d/rds.conf

              

Result for Disable TIPC Support

Result: pass

Rule ID: kernel_module_tipc_disabled

Time: 2014-07-16 17:33

Severity: medium

The Transparent Inter-Process Communication (TIPC) protocol is designed to provide communications between nodes in a cluster. To configure the system to prevent the tipc kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d:

install tipc /bin/false

Disabling TIPC protects the system against exploitation of any flaws in its implementation.

Security identifiers

  • CCE-26696-5

Remediation script

                echo "install tipc /bin/false" > /etc/modprobe.d/tipc.conf

              

Result for Ensure rsyslog is Installed

Result: pass

Rule ID: package_rsyslog_installed

Time: 2014-07-16 17:33

Severity: medium

Rsyslog is installed by default. The rsyslog package can be installed with the following command:

# yum install rsyslog

The rsyslog package provides the rsyslog daemon, which provides system logging services.

Security identifiers

  • CCE-26809-4

Remediation script

                yum -y install rsyslog

              

Result for Enable rsyslog Service

Result: pass

Rule ID: service_rsyslog_enabled

Time: 2014-07-16 17:33

Severity: medium

The rsyslog service provides syslog-style logging by default on RHEL 6. The rsyslog service can be enabled with the following command:

# chkconfig --level 2345 rsyslog on

The rsyslog service must be running in order to provide logging services, which are essential to system administration.

Security identifiers

  • CCE-26807-8

Remediation script

                #
# Enable rsyslog for all run levels
#
chkconfig --level 0123456 rsyslog on

#
# Start rsyslog if not currently running
#
service rsyslog start

              

Result for Ensure Log Files Are Owned By Appropriate Group

Result: unknown

Rule ID: groupowner_rsyslog_files

Time: 2014-07-16 17:33

Severity: medium

The group-owner of all log files written by rsyslog should be root. These log files are determined by the second part of each Rule line in /etc/rsyslog.conf and typically all appear in /var/log. For each log file LOGFILE referenced in /etc/rsyslog.conf, run the following command to inspect the file's group owner:

$ ls -l LOGFILE
If the owner is not root, run the following command to correct this:
# chgrp root LOGFILE

The log files generated by rsyslog contain valuable information regarding system configuration, user authentication, and other such information. Log files should be protected from unauthorized access.

Security identifiers

  • CCE-26821-9

Result for Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server

Result: pass

Rule ID: rsyslog_accept_remote_messages_none

Time: 2014-07-16 17:33

Severity: low

The rsyslog daemon should not accept remote messages unless the system acts as a log server. To ensure that it is not listening on the network, ensure the following lines are not found in /etc/rsyslog.conf:

$ModLoad imtcp
$InputTCPServerRun port
$ModLoad imudp
$UDPServerRun port
$ModLoad imrelp
$InputRELPServerRun port

Any process which receives messages from the network incurs some risk of receiving malicious messages. This risk can be eliminated for rsyslog by configuring it not to listen on the network.

Security identifiers

  • CCE-26803-7

Result for Enable rsyslog to Accept Messages via TCP, if Acting As Log Server

Result: notchecked

Rule ID: rsyslog_accept_remote_messages_tcp

Time: 2014-07-16 17:33

Severity: low

The rsyslog daemon should not accept remote messages unless the system acts as a log server. If the system needs to act as a central log server, add the following lines to /etc/rsyslog.conf to enable reception of messages over TCP:

$ModLoad imtcp
$InputTCPServerRun 514

If the system needs to act as a log server, this ensures that it can receive messages over a reliable TCP connection.

Security identifiers

  • CCE-27235-1

Result for Enable rsyslog to Accept Messages via UDP, if Acting As Log Server

Result: notchecked

Rule ID: rsyslog_accept_remote_messages_udp

Time: 2014-07-16 17:33

Severity: low

The rsyslog daemon should not accept remote messages unless the system acts as a log server. If the system needs to act as a central log server, add the following lines to /etc/rsyslog.conf to enable reception of messages over UDP:

$ModLoad imudp
$UDPServerRun 514

Many devices, such as switches, routers, and other Unix-like systems, may only support the traditional syslog transmission over UDP. If the system must act as a log server, this enables it to receive their messages as well.

Security identifiers

  • CCE-27236-9

Result for Ensure Logrotate Runs Periodically

Result: pass

Rule ID: ensure_logrotate_activated

Time: 2014-07-16 17:33

Severity: low

The logrotate utility allows for the automatic rotation of log files. The frequency of rotation is specified in /etc/logrotate.conf, which triggers a cron task. To configure logrotate to run daily, add or correct the following line in /etc/logrotate.conf:

# rotate log files frequency
daily

Log files that are not properly rotated run the risk of growing so large that they fill up the /var/log partition. Valuable logging information could be lost if the /var/log partition becomes full.

Security identifiers

  • CCE-27014-0

Result for Enable auditd Service

Result: pass

Rule ID: service_auditd_enabled

Time: 2014-07-16 17:33

Severity: medium

The auditd service is an essential userspace component of the Linux Auditing System, as it is responsible for writing audit records to disk. The auditd service can be enabled with the following command:

# chkconfig --level 2345 auditd on

Ensuring the auditd service is active ensures audit records generated by the kernel can be written to disk, or that appropriate actions will be taken if other obstacles exist.

Security identifiers

  • CCE-27058-7

Remediation script

                #
# Enable auditd for all run levels
#
chkconfig --level 0123456 auditd on

#
# Start auditd if not currently running
#
service auditd start

              

Result for Enable Auditing for Processes Which Start Prior to the Audit Daemon

Result: pass

Rule ID: enable_auditd_bootloader

Time: 2014-07-16 17:33

Severity: medium

To ensure all processes can be audited, even those which start prior to the audit daemon, add the argument audit=1 to the kernel line in /etc/grub.conf, in the manner below:

kernel /vmlinuz-version ro vga=ext root=/dev/VolGroup00/LogVol00 rhgb quiet audit=1

Each process on the system carries an "auditable" flag which indicates whether its activities can be audited. Although auditd takes care of enabling this for all processes which launch after it does, adding the kernel argument ensures it is set for every process during boot.

Security identifiers

  • CCE-26785-6

Result for Configure auditd Number of Logs Retained

Result: pass

Rule ID: configure_auditd_num_logs

Time: 2014-07-16 17:33

Severity: medium

Determine how many log files auditd should retain when it rotates logs. Edit the file /etc/audit/auditd.conf. Add or modify the following line, substituting NUMLOGS with the correct value:

num_logs = NUMLOGS
Set the value to 5 for general-purpose systems. Note that values less than 2 result in no log rotation.

The total storage for audit log files must be large enough to retain log information over the period required. This is a function of the maximum log file size and the number of logs retained.

Security identifiers

  • CCE-27522-2

Result for Configure auditd Max Log File Size

Result: pass

Rule ID: configure_auditd_max_log_file

Time: 2014-07-16 17:33

Severity: medium

Determine the amount of audit data (in megabytes) which should be retained in each log file. Edit the file /etc/audit/auditd.conf. Add or modify the following line, substituting the correct value for STOREMB:

max_log_file = STOREMB
Set the value to 6 (MB) or higher for general-purpose systems. Larger values, of course, support retention of even more audit data.

The total storage for audit log files must be large enough to retain log information over the period required. This is a function of the maximum log file size and the number of logs retained.

Security identifiers

  • CCE-27550-3

Result for Configure auditd max_log_file_action Upon Reaching Maximum Log Size

Result: pass

Rule ID: configure_auditd_max_log_file_action

Time: 2014-07-16 17:33

Severity: medium

The default action to take when the logs reach their maximum size is to rotate the log files, discarding the oldest one. To configure the action taken by auditd, add or correct the line in /etc/audit/auditd.conf:

max_log_file_action = ACTION
Possible values for ACTION are described in the auditd.conf man page. These include:

  • ignore

  • syslog

  • suspend

  • rotate

  • keep_logs

Set the ACTION to rotate to ensure log rotation occurs. This is the default. The setting is case-insensitive.

Automatically rotating logs (by setting this to rotate) minimizes the chances of the system unexpectedly running out of disk space by being overwhelmed with log data. However, for systems that must never discard log data, or which use external processes to transfer it and reclaim space, keep_logs can be employed.

Security identifiers

  • CCE-27237-7

Result for Configure auditd space_left Action on Low Disk Space

Result: pass

Rule ID: auditd_data_retention_space_left_action

Time: 2014-07-16 17:33

Severity: medium

The auditd service can be configured to take an action when disk space starts to run low. Edit the file /etc/audit/auditd.conf. Modify the following line, substituting ACTION appropriately:

space_left_action = ACTION
Possible values for ACTION are described in the auditd.conf man page. These include:

  • ignore

  • syslog

  • email

  • exec

  • suspend

  • single

  • halt

Set this to email (instead of the default, which is suspend) as it is more likely to get prompt attention. Acceptable values also include suspend, single, and halt.

Notifying administrators of an impending disk space problem may allow them to take corrective action prior to any disruption.

Security identifiers

  • CCE-27238-5

Result for Configure auditd admin_space_left Action on Low Disk Space

Result: pass

Rule ID: auditd_data_retention_admin_space_left_action

Time: 2014-07-16 17:33

Severity: medium

The auditd service can be configured to take an action when disk space is running low but prior to running out of space completely. Edit the file /etc/audit/auditd.conf. Add or modify the following line, substituting ACTION appropriately:

admin_space_left_action = ACTION
Set this value to single to cause the system to switch to single user mode for corrective action. Acceptable values also include suspend and halt. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. Details regarding all possible values for ACTION are described in the auditd.conf man page.

Administrators should be made aware of an inability to record audit records. If a separate partition or logical volume of adequate size is used, running low on space for audit records should never occur.

Security identifiers

  • CCE-27239-3

Remediation script

                var_auditd_admin_space_left_action="single"
grep -q ^admin_space_left_action /etc/audit/auditd.conf && \
  sed -i "s/admin_space_left_action.*/admin_space_left_action = $var_auditd_admin_space_left_action/g" /etc/audit/auditd.conf
if ! [ $? -eq 0 ]; then
    echo "admin_space_left_action = $var_auditd_admin_space_left_action" >> /etc/audit/auditd.conf
fi

              

Result for Configure auditd mail_acct Action on Low Disk Space

Result: pass

Rule ID: auditd_data_retention_action_mail_acct

Time: 2014-07-16 17:33

Severity: medium

The auditd service can be configured to send email to a designated account in certain situations. Add or correct the following line in /etc/audit/auditd.conf to ensure that administrators are notified via email for those situations:

action_mail_acct = root

Email sent to the root account is typically aliased to the administrators of the system, who can take appropriate action.

Security identifiers

  • CCE-27241-9

Result for Configure auditd to use audispd plugin

Result: notchecked

Rule ID: configure_auditd_audispd

Time: 2014-07-16 17:33

Severity: medium

To configure the auditd service to use the audispd plugin, set the active line in /etc/audisp/plugins.d/syslog.conf to yes. Restart the auditdservice:

# service auditd restart

The auditd service does not include the ability to send audit records to a centralized server for management directly. It does, however, include an audit event multiplexor plugin (audispd) to pass audit records to the local syslog server

Security identifiers

  • CCE-26933-2

Result for Record attempts to alter time through adjtimex

Result: pass

Rule ID: audit_rules_time_adjtimex

Time: 2014-07-16 17:33

Severity: low

On a 32-bit system, add the following to /etc/audit/audit.rules:

# audit_time_rules
-a always,exit -F arch=b32 -S adjtimex -k audit_time_rules
On a 64-bit system, add the following to /etc/audit/audit.rules:
# audit_time_rules
-a always,exit -F arch=b64 -S adjtimex -k audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime 
-k audit_time_rules

Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.

Security identifiers

  • CCE-26242-8

Result for Record attempts to alter time through settimeofday

Result: pass

Rule ID: audit_rules_time_settimeofday

Time: 2014-07-16 17:33

Severity: low

On a 32-bit system, add the following to /etc/audit/audit.rules:

# audit_time_rules
-a always,exit -F arch=b32 -S settimeofday -k audit_time_rules
On a 64-bit system, add the following to /etc/audit/audit.rules:
# audit_time_rules
-a always,exit -F arch=b64 -S settimeofday -k audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime 
-k audit_time_rules

Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.

Security identifiers

  • CCE-27203-9

Result for Record Attempts to Alter Time Through stime

Result: pass

Rule ID: audit_rules_time_stime

Time: 2014-07-16 17:33

Severity: low

On a 32-bit system, add the following to /etc/audit/audit.rules:

# audit_time_rules
-a always,exit -F arch=b32 -S stime -k audit_time_rules
On a 64-bit system, the "-S stime" is not necessary. The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime 
-k audit_time_rules

Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.

Security identifiers

  • CCE-27169-2

Result for Record Attempts to Alter Time Through clock_settime

Result: pass

Rule ID: audit_rules_time_clock_settime

Time: 2014-07-16 17:33

Severity: low

On a 32-bit system, add the following to /etc/audit/audit.rules:

# audit_time_rules
-a always,exit -F arch=b32 -S clock_settime -k audit_time_rules
On a 64-bit system, add the following to /etc/audit/audit.rules:
# audit_time_rules
-a always,exit -F arch=b64 -S clock_settime -k audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime 
-k audit_time_rules

Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.

Security identifiers

  • CCE-27170-0

Result for Record Attempts to Alter the localtime File

Result: pass

Rule ID: audit_rules_time_watch_localtime

Time: 2014-07-16 17:33

Severity: low

Add the following to /etc/audit/audit.rules:

-w /etc/localtime -p wa -k audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport and should always be used.

Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.

Security identifiers

  • CCE-27172-6

Result for Record Events that Modify User/Group Information

Result: pass

Rule ID: audit_account_changes

Time: 2014-07-16 17:33

Severity: low

Add the following to /etc/audit/audit.rules, in order to capture events that modify account changes:

# audit_account_changes
-w /etc/group -p wa -k audit_account_changes
-w /etc/passwd -p wa -k audit_account_changes
-w /etc/gshadow -p wa -k audit_account_changes
-w /etc/shadow -p wa -k audit_account_changes
-w /etc/security/opasswd -p wa -k audit_account_changes

In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.

Security identifiers

  • CCE-26664-3

Result for Record Events that Modify the System's Network Environment

Result: pass

Rule ID: audit_network_modifications

Time: 2014-07-16 17:33

Severity: low

Add the following to /etc/audit/audit.rules, setting ARCH to either b32 or b64 as appropriate for your system:

# audit_network_modifications
-a always,exit -F arch=ARCH -S sethostname -S setdomainname -k audit_network_modifications
-w /etc/issue -p wa -k audit_network_modifications
-w /etc/issue.net -p wa -k audit_network_modifications
-w /etc/hosts -p wa -k audit_network_modifications
-w /etc/sysconfig/network -p wa -k audit_network_modifications

The network environment should not be modified by anything other than administrator action. Any change to network parameters should be audited.

Security identifiers

  • CCE-26648-6

Result for System Audit Logs Must Have Mode 0640 or Less Permissive

Result: pass

Rule ID: file_permissions_var_log_audit

Time: 2014-07-16 17:33

Severity: low

Change the mode of the audit log files with the following command:

# chmod 0640 audit_file

If users can write to audit logs, audit trails can be modified or destroyed.

Security identifiers

  • CCE-27243-5

Result for System Audit Logs Must Be Owned By Root

Result: pass

Rule ID: audit_logs_rootowner

Time: 2014-07-16 17:33

Severity: low

To properly set the owner of /var/log, run the command:

# chown root /var/log 

Failure to give ownership of the audit log files to root allows the designated owner, and unauthorized users, potential access to sensitive information.

Security identifiers

  • CCE-27244-3

Result for Record Events that Modify the System's Mandatory Access Controls

Result: pass

Rule ID: audit_mac_changes

Time: 2014-07-16 17:33

Severity: low

Add the following to /etc/audit/audit.rules:

-w /etc/selinux/ -p wa -k MAC-policy

The system's mandatory access policy (SELinux) should not be arbitrarily changed by anything other than administrator action. All changes to MAC policy should be audited.

Security identifiers

  • CCE-26657-7

Result for Record Events that Modify the System's Discretionary Access Controls - chmod

Result: pass

Rule ID: audit_rules_dac_modification_chmod

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S chmod -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S chmod  -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-26280-8

Result for Record Events that Modify the System's Discretionary Access Controls - chown

Result: pass

Rule ID: audit_rules_dac_modification_chown

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S chown -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S chown -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27173-4

Result for Record Events that Modify the System's Discretionary Access Controls - fchmod

Result: pass

Rule ID: audit_rules_dac_modification_fchmod

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S fchmod -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchmod -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27174-2

Result for Record Events that Modify the System's Discretionary Access Controls - fchmodat

Result: pass

Rule ID: audit_rules_dac_modification_fchmodat

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S fchmodat -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchmodat -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27175-9

Result for Record Events that Modify the System's Discretionary Access Controls - fchown

Result: pass

Rule ID: audit_rules_dac_modification_fchown

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S fchown -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchown -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27177-5

Result for Record Events that Modify the System's Discretionary Access Controls - fchownat

Result: pass

Rule ID: audit_rules_dac_modification_fchownat

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S fchownat -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchownat -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27178-3

Result for Record Events that Modify the System's Discretionary Access Controls - fremovexattr

Result: pass

Rule ID: audit_rules_dac_modification_fremovexattr

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S fremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27179-1

Result for Record Events that Modify the System's Discretionary Access Controls - fsetxattr

Result: pass

Rule ID: audit_rules_dac_modification_fsetxattr

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S fsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27180-9

Result for Record Events that Modify the System's Discretionary Access Controls - lchown

Result: pass

Rule ID: audit_rules_dac_modification_lchown

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S lchown -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S lchown -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27181-7

Result for Record Events that Modify the System's Discretionary Access Controls - lremovexattr

Result: pass

Rule ID: audit_rules_dac_modification_lremovexattr

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S lremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S lremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27182-5

Result for Record Events that Modify the System's Discretionary Access Controls - lsetxattr

Result: pass

Rule ID: audit_rules_dac_modification_lsetxattr

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S lsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S lsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27183-3

Result for Record Events that Modify the System's Discretionary Access Controls - removexattr

Result: pass

Rule ID: audit_rules_dac_modification_removexattr

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S removexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S removexattr -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27184-1

Result for Record Events that Modify the System's Discretionary Access Controls - setxattr

Result: pass

Rule ID: audit_rules_dac_modification_setxattr

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect file permission changes for all users and root. Add the following to /etc/audit/audit.rules:

-a always,exit -F arch=b32 -S setxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S setxattr -F auid>=500 -F auid!=4294967295 -k perm_mod

Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.

The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.

Security identifiers

  • CCE-27185-8

Result for Record Attempts to Alter Logon and Logout Events

Result: pass

Rule ID: audit_manual_logon_edits

Time: 2014-07-16 17:33

Severity: low

The audit system already collects login info for all users and root. To watch for attempted manual edits of files involved in storing logon events, add the following to /etc/audit/audit.rules:

-w /var/log/faillog -p wa -k logins 
-w /var/log/lastlog -p wa -k logins

Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.

Security identifiers

  • CCE-26691-6

Result for Record Attempts to Alter Process and Session Initiation Information

Result: pass

Rule ID: audit_manual_session_edits

Time: 2014-07-16 17:33

Severity: low

The audit system already collects process information for all users and root. To watch for attempted manual edits of files involved in storing such process information, add the following to /etc/audit/audit.rules:

-w /var/run/utmp -p wa -k session
-w /var/log/btmp -p wa -k session
-w /var/log/wtmp -p wa -k session

Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.

Security identifiers

  • CCE-26610-6

Result for Ensure auditd Collects Information on the Use of Privileged Commands

Result: notchecked

Rule ID: audit_privileged_commands

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect the execution of privileged commands for all users and root. To find the relevant setuid programs:

# find / -xdev -type f -perm -4000 -o -perm -2000 2>/dev/null
Then, for each setuid program on the system, add a line of the following form to /etc/audit/audit.rules, where SETUID_PROG_PATH is the full path to each setuid program in the list:
-a always,exit -F path=SETUID_PROG_PATH -F perm=x -F auid>=500 -F auid!=4294967295 -k privileged

Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.

Security identifiers

  • CCE-26457-2

Result for Ensure auditd Collects Information on Exporting to Media (successful)

Result: pass

Rule ID: audit_media_exports

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect media exportation events for all users and root. Add the following to /etc/audit/audit.rules, setting ARCH to either b32 or b64 as appropriate for your system:

-a always,exit -F arch=ARCH -S mount -F auid>=500 -F auid!=4294967295 -k export

The unauthorized exportation of data to external media could result in an information leak where classified information, Privacy Act information, and intellectual property could be lost. An audit trail should be created each time a filesystem is mounted to help identify and guard against information loss.

Security identifiers

  • CCE-26573-6

Result for Ensure auditd Collects System Administrator Actions

Result: pass

Rule ID: audit_sysadmin_actions

Time: 2014-07-16 17:33

Severity: low

At a minimum the audit system should collect administrator actions for all users and root. Add the following to /etc/audit/audit.rules:

-w /etc/sudoers -p wa -k actions

The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes.

Security identifiers

  • CCE-26662-7

Result for Ensure auditd Collects Information on Kernel Module Loading and Unloading

Result: pass

Rule ID: audit_kernel_module_loading

Time: 2014-07-16 17:33

Severity: low

Add the following to /etc/audit/audit.rules in order to capture kernel module loading and unloading events, setting ARCH to either b32 or b64 as appropriate for your system:

-w /sbin/insmod -p x -k modules
-w /sbin/rmmod -p x -k modules
-w /sbin/modprobe -p x -k modules
-a always,exit -F arch=ARCH -S init_module -S delete_module -k modules

The addition/removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.

Security identifiers

  • CCE-26611-4

Result for Make the auditd Configuration Immutable

Result: pass

Rule ID: audit_config_immutable

Time: 2014-07-16 17:33

Severity: low

Add the following to /etc/audit/audit.rules in order to make the configuration immutable:

-e 2
With this setting, a reboot will be required to change any audit rules.

Making the audit configuration immutable prevents accidental as well as malicious modification of the audit rules, although it may be problematic if legitimate changes are needed during system operation

Security identifiers

  • CCE-26612-2

Result for Uninstall rsh-server Package

Result: pass

Rule ID: uninstall_rsh-server

Time: 2014-07-16 17:33

Severity: high

The rsh-server package can be uninstalled with the following command:

# yum erase rsh-server

The rsh-server package provides several obsolete and insecure network services. Removing it decreases the risk of those services' accidental (or intentional) activation.

Security identifiers

  • CCE-27062-9

Result for Disable rexec Service

Result: pass

Rule ID: disable_rexec

Time: 2014-07-16 17:33

Severity: high

The rexec service, which is available with the rsh-server package and runs as a service through xinetd, should be disabled. The rexec service can be disabled with the following command:

# chkconfig rexec off

The rexec service uses unencrypted network communications, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network.

Security identifiers

  • CCE-27208-8

Result for Disable rsh Service

Result: pass

Rule ID: disable_rsh

Time: 2014-07-16 17:33

Severity: high

The rsh service, which is available with the rsh-server package and runs as a service through xinetd, should be disabled. The rsh service can be disabled with the following command:

# chkconfig rsh off

The rsh service uses unencrypted network communications, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network.

Security identifiers

  • CCE-26994-4

Result for Disable rlogin Service

Result: pass

Rule ID: disable_rlogin

Time: 2014-07-16 17:33

Severity: high

The rlogin service, which is available with the rsh-server package and runs as a service through xinetd, should be disabled. The rlogin service can be disabled with the following command:

# chkconfig rlogin off

The rlogin service uses unencrypted network communications, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network.

Security identifiers

  • CCE-26865-6

Result for Uninstall ypserv Package

Result: pass

Rule ID: uninstall_ypserv

Time: 2014-07-16 17:33

Severity: medium

The ypserv package can be uninstalled with the following command:

# yum erase ypserv

Removing the ypserv package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services.

Security identifiers

  • CCE-27079-3

Remediation script

                if rpm -qa | grep -q ypserv; then
	yum -y remove ypserv
fi

              

Result for Disable ypbind Service

Result: pass

Rule ID: disable_ypbind

Time: 2014-07-16 17:33

Severity: medium

The ypbind service, which allows the system to act as a client in a NIS or NIS+ domain, should be disabled. The ypbind service can be disabled with the following command:

# chkconfig ypbind off

Disabling the ypbind service ensures the system is not acting as a client in a NIS or NIS+ domain.

Security identifiers

  • CCE-26894-6

Result for Disable tftp Service

Result: pass

Rule ID: disable_tftp

Time: 2014-07-16 17:33

Severity: medium

The tftp service should be disabled. The tftp service can be disabled with the following command:

# chkconfig tftp off

Disabling the tftp service ensures the system is not acting as a TFTP server, which does not provide encryption or authentication.

Security identifiers

  • CCE-27055-3

Result for Uninstall tftp-server Package

Result: pass

Rule ID: uninstall_tftp-server

Time: 2014-07-16 17:33

Severity: medium

The tftp-server package can be removed with the following command:

# yum erase tftp-server

Removing the tftp-server package decreases the risk of the accidental (or intentional) activation of tftp services.

Security identifiers

  • CCE-26946-4

Result for Ensure tftp Daemon Uses Secure Mode

Result: pass

Rule ID: tftpd_uses_secure_mode

Time: 2014-07-16 17:33

Severity: high

If running the tftp service is necessary, it should be configured to change its root directory at startup. To do so, ensure /etc/xinetd.d/tftp includes -s as a command line argument, as shown in the following example (which is also the default):

server_args = -s /var/lib/tftpboot

Using the -s option causes the TFTP service to only serve files from the given directory. Serving files from an intentionally-specified directory reduces the risk of sharing files which should remain private.

Security identifiers

  • CCE-27272-4

Result for Disable Automatic Bug Reporting Tool (abrtd)

Result: pass

Rule ID: service_abrtd_disabled

Time: 2014-07-16 17:33

Severity: low

The Automatic Bug Reporting Tool (abrtd) daemon collects and reports crash data when an application crash is detected. Using a variety of plugins, abrtd can email crash reports to system administrators, log crash reports to files, or forward crash reports to a centralized issue tracking system such as RHTSupport. The abrtd service can be disabled with the following command:

# chkconfig abrtd off

Mishandling crash data could expose sensitive information about vulnerabilities in software executing on the local machine, as well as sensitive information from within a process's address space or registers.

Security identifiers

  • CCE-27247-6

Remediation script

                #
# Disable abrtd for all run levels
#
chkconfig --level 0123456 abrtd off

#
# Stop abrtd if currently running
#
service abrtd stop

              

Result for Disable Advanced Configuration and Power Interface (acpid)

Result: pass

Rule ID: service_acpid_disabled

Time: 2014-07-16 17:33

Severity: low

The Advanced Configuration and Power Interface Daemon (acpid) dispatches ACPI events (such as power/reset button depressed) to userspace programs. The acpid service can be disabled with the following command:

# chkconfig acpid off

ACPI support is highly desirable for systems in some network roles, such as laptops or desktops. For other systems, such as servers, it may permit accidental or trivially achievable denial of service situations and disabling it is appropriate.

Security identifiers

  • CCE-27061-1

Remediation script

                #
# Disable acpid for all run levels
#
chkconfig --level 0123456 acpid off

#
# Stop acpid if currently running
#
service acpid stop

              

Result for Disable Certmonger Service (certmonger)

Result: pass

Rule ID: service_certmonger_disabled

Time: 2014-07-16 17:33

Severity: low

Certmonger is a D-Bus based service that attempts to simplify interaction with certifying authorities on networks which use public-key infrastructure. It is often combined with Red Hat's IPA (Identity Policy Audit) security information management solution to aid in the management of certificates. The certmonger service can be disabled with the following command:

# chkconfig certmonger off

The services provided by certmonger may be essential for systems fulfilling some roles a PKI infrastructure, but its functionality is not necessary for many other use cases.

Security identifiers

  • CCE-27267-4

Remediation script

                #
# Disable certmonger for all run levels
#
chkconfig --level 0123456 certmonger off

#
# Stop certmonger if currently running
#
service certmonger stop

              

Result for Disable Control Group Config (cgconfig)

Result: pass

Rule ID: service_cgconfig_disabled

Time: 2014-07-16 17:33

Severity: low

Control groups allow an administrator to allocate system resources (such as CPU, memory, network bandwidth, etc) among a defined group (or groups) of processes executing on a system. The cgconfig daemon starts at boot and establishes the predefined control groups. The cgconfig service can be disabled with the following command:

# chkconfig cgconfig off

Unless control groups are used to manage system resources, running the cgconfig service is not necessary.

Security identifiers

  • CCE-27250-0

Remediation script

                #
# Disable cgconfig for all run levels
#
chkconfig --level 0123456 cgconfig off

#
# Stop cgconfig if currently running
#
service cgconfig stop

              

Result for Disable CPU Speed (cpuspeed)

Result: pass

Rule ID: service_cpuspeed_disabled

Time: 2014-07-16 17:33

Severity: low

The cpuspeed service can adjust the clock speed of supported CPUs based upon the current processing load thereby conserving power and reducing heat. The cpuspeed service can be disabled with the following command:

# chkconfig cpuspeed off

The cpuspeed service is only necessary if adjusting the CPU clock speed provides benefit. Traditionally this has included laptops (to enhance battery life), but may also apply to server or desktop environments where conserving power is highly desirable or necessary.

Security identifiers

  • CCE-26973-8

Remediation script

                #
# Disable cpuspeed for all run levels
#
chkconfig --level 0123456 cpuspeed off

#
# Stop cpuspeed if currently running
#
service cpuspeed stop

              

Result for Disable Hardware Abstraction Layer Service (haldaemon)

Result: pass

Rule ID: service_haldaemon_disabled

Time: 2014-07-16 17:33

Severity: low

The Hardware Abstraction Layer Daemon (haldaemon) collects and maintains information about the system's hardware configuration. This service is required on a workstation running a desktop environment, and may be necessary on any system which deals with removable media or devices. The haldaemon service can be disabled with the following command:

# chkconfig haldaemon off

The haldaemon provides essential functionality on systems that use removable media or devices, but can be disabled for systems that do not require these.

Security identifiers

  • CCE-27086-8

Remediation script

                #
# Disable haldaemon for all run levels
#
chkconfig --level 0123456 haldaemon off

#
# Stop haldaemon if currently running
#
service haldaemon stop

              

Result for Disable Software RAID Monitor (mdmonitor)

Result: pass

Rule ID: service_mdmonitor_disabled

Time: 2014-07-16 17:33

Severity: low

The mdmonitor service is used for monitoring a software RAID array; hardware RAID setups do not use this service. The mdmonitor service can be disabled with the following command:

# chkconfig mdmonitor off

If software RAID monitoring is not required, there is no need to run this service.

Security identifiers

  • CCE-27193-2

Remediation script

                #
# Disable mdmonitor for all run levels
#
chkconfig --level 0123456 mdmonitor off

#
# Stop mdmonitor if currently running
#
service mdmonitor stop

              

Result for Disable D-Bus IPC Service (messagebus)

Result: pass

Rule ID: service_messagebus_disabled

Time: 2014-07-16 17:33

Severity: low

D-Bus provides an IPC mechanism used by a growing list of programs, such as those used for Gnome, Bluetooth, and Avahi. Due to these dependencies, disabling D-Bus may not be practical for many systems. The messagebus service can be disabled with the following command:

# chkconfig messagebus off

If no services which require D-Bus are needed, then it can be disabled. As a broker for IPC between processes of different privilege levels, it could be a target for attack. However, disabling D-Bus is likely to be impractical for any system which needs to provide a graphical login session.

Security identifiers

  • CCE-26913-4

Remediation script

                #
# Disable messagebus for all run levels
#
chkconfig --level 0123456 messagebus off

#
# Stop messagebus if currently running
#
service messagebus stop

              

Result for Disable Network Console (netconsole)

Result: pass

Rule ID: service_netconsole_disabled

Time: 2014-07-16 17:33

Severity: low

The netconsole service is responsible for loading the netconsole kernel module, which logs kernel printk messages over UDP to a syslog server. This allows debugging of problems where disk logging fails and serial consoles are impractical. The netconsole service can be disabled with the following command:

# chkconfig netconsole off

The netconsole service is not necessary unless there is a need to debug kernel panics, which is not common.

Security identifiers

  • CCE-27254-2

Remediation script

                #
# Disable netconsole for all run levels
#
chkconfig --level 0123456 netconsole off

#
# Stop netconsole if currently running
#
service netconsole stop

              

Result for Disable ntpdate Service (ntpdate)

Result: pass

Rule ID: service_ntpdate_disabled

Time: 2014-07-16 17:33

Severity: low

The ntpdate service sets the local hardware clock by polling NTP servers when the system boots. It synchronizes to the NTP servers listed in /etc/ntp/step-tickers or /etc/ntp.conf and then sets the local hardware clock to the newly synchronized system time. The ntpdate service can be disabled with the following command:

# chkconfig ntpdate off

The ntpdate service may only be suitable for systems which are rebooted frequently enough that clock drift does not cause problems between reboots. In any event, the functionality of the ntpdate service is now available in the ntpd program and should be considered deprecated.

Security identifiers

  • CCE-27256-7

Result for Disable Odd Job Daemon (oddjobd)

Result: pass

Rule ID: service_oddjobd_disabled

Time: 2014-07-16 17:33

Severity: low

The oddjobd service exists to provide an interface and access control mechanism through which specified privileged tasks can run tasks for unprivileged client applications. Communication with oddjobd through the system message bus. The oddjobd service can be disabled with the following command:

# chkconfig oddjobd off

The oddjobd service may provide necessary functionality in some environments, and can be disabled if it is not needed. Execution of tasks by privileged programs, on behalf of unprivileged ones, has traditionally been a source of privilege escalation security issues.

Security identifiers

  • CCE-27257-5

Remediation script

                #
# Disable oddjobd for all run levels
#
chkconfig --level 0123456 oddjobd off

#
# Stop oddjobd if currently running
#
service oddjobd stop

              

Result for Disable Portreserve (portreserve)

Result: pass

Rule ID: service_portreserve_disabled

Time: 2014-07-16 17:33

Severity: low

The portreserve service is a TCP port reservation utility that can be used to prevent portmap from binding to well known TCP ports that are required for other services. The portreserve service can be disabled with the following command:

# chkconfig portreserve off

The portreserve service provides helpful functionality by preventing conflicting usage of ports in the reserved port range, but it can be disabled if not needed.

Security identifiers

  • CCE-27258-3

Remediation script

                #
# Disable portreserve for all run levels
#
chkconfig --level 0123456 portreserve off

#
# Stop portreserve if currently running
#
service portreserve stop

              

Result for Enable Process Accounting (psacct)

Result: pass

Rule ID: service_psacct_enabled

Time: 2014-07-16 17:33

Severity: low

The process accounting service, psacct, works with programs including acct and ac to allow system administrators to view user activity, such as commands issued by users of the system. The psacct service can be enabled with the following command:

# chkconfig --level 2345 psacct on

The psacct service can provide administrators a convenient view into some user activities. However, it should be noted that the auditing system and its audit records provide more authoritative and comprehensive records.

Security identifiers

  • CCE-27259-1

Remediation script

                #
# Enable psacct for all run levels
#
chkconfig --level 0123456 psacct on

#
# Start psacct if not currently running
#
service psacct start

              

Result for Disable Apache Qpid (qpidd)

Result: pass

Rule ID: service_qpidd_disabled

Time: 2014-07-16 17:33

Severity: low

The qpidd service provides high speed, secure, guaranteed delivery services. It is an implementation of the Advanced Message Queuing Protocol. By default the qpidd service will bind to port 5672 and listen for connection attempts. The qpidd service can be disabled with the following command:

# chkconfig qpidd off

The qpidd service is automatically installed when the "base" package selection is selected during installation. The qpidd service listens for network connections, which increases the attack surface of the system. If the system is not intended to receive AMQP traffic, then the qpidd service is not needed and should be disabled or removed.

Security identifiers

  • CCE-26928-2

Remediation script

                #
# Disable qpidd for all run levels
#
chkconfig --level 0123456 qpidd off

#
# Stop qpidd if currently running
#
service qpidd stop

              

Result for Disable Quota Netlink (quota_nld)

Result: pass

Rule ID: service_quota_nld_disabled

Time: 2014-07-16 17:33

Severity: low

The quota_nld service provides notifications to users of disk space quota violations. It listens to the kernel via a netlink socket for disk quota violations and notifies the appropriate user of the violation using D-Bus or by sending a message to the terminal that the user has last accessed. The quota_nld service can be disabled with the following command:

# chkconfig quota_nld off

If disk quotas are enforced on the local system, then the quota_nld service likely provides useful functionality and should remain enabled. However, if disk quotas are not used or user notification of disk quota violation is not desired then there is no need to run this service.

Security identifiers

  • CCE-27260-9

Remediation script

                #
# Disable quota_nld for all run levels
#
chkconfig --level 0123456 quota_nld off

#
# Stop quota_nld if currently running
#
service quota_nld stop

              

Result for Disable Network Router Discovery Daemon (rdisc)

Result: pass

Rule ID: service_rdisc_disabled

Time: 2014-07-16 17:33

Severity: low

The rdisc service implements the client side of the ICMP Internet Router Discovery Protocol (IRDP), which allows discovery of routers on the local subnet. If a router is discovered then the local routing table is updated with a corresponding default route. By default this daemon is disabled. The rdisc service can be disabled with the following command:

# chkconfig rdisc off

General-purpose systems typically have their network and routing information configured statically by a system administrator. Workstations or some special-purpose systems often use DHCP (instead of IRDP) to retrieve dynamic network configuration information.

Security identifiers

  • CCE-27261-7

Remediation script

                #
# Disable rdisc for all run levels
#
chkconfig --level 0123456 rdisc off

#
# Stop rdisc if currently running
#
service rdisc stop

              

Result for Disable Red Hat Network Service (rhnsd)

Result: pass

Rule ID: service_rhnsd_disabled

Time: 2014-07-16 17:33

Severity: low

The Red Hat Network service automatically queries Red Hat Network servers to determine whether there are any actions that should be executed, such as package updates. This only occurs if the system was registered to an RHN server or satellite and managed as such. The rhnsd service can be disabled with the following command:

# chkconfig rhnsd off

Although systems management and patching is extremely important to system security, management by a system outside the enterprise enclave is not desirable for some environments. However, if the system is being managed by RHN or RHN Satellite Server the rhnsd daemon can remain on.

Security identifiers

  • CCE-26846-6

Remediation script

                #
# Disable rhnsd for all run levels
#
chkconfig --level 0123456 rhnsd off

#
# Stop rhnsd if currently running
#
service rhnsd stop

              

Result for Disable Red Hat Subscription Manager Daemon (rhsmcertd)

Result: pass

Rule ID: service_rhsmcertd_disabled

Time: 2014-07-16 17:33

Severity: low

The Red Hat Subscription Manager (rhsmcertd) periodically checks for changes in the entitlement certificates for a registered system and updates it accordingly. The rhsmcertd service can be disabled with the following command:

# chkconfig rhsmcertd off

The rhsmcertd service can provide administrators with some additional control over which of their systems are entitled to particular subscriptions. However, for systems that are managed locally or which are not expected to require remote changes to their subscription status, it is unnecessary and can be disabled.

Security identifiers

  • CCE-27262-5

Remediation script

                #
# Disable rhsmcertd for all run levels
#
chkconfig --level 0123456 rhsmcertd off

#
# Stop rhsmcertd if currently running
#
service rhsmcertd stop

              

Result for Disable Cyrus SASL Authentication Daemon (saslauthd)

Result: pass

Rule ID: service_saslauthd_disabled

Time: 2014-07-16 17:33

Severity: low

The saslauthd service handles plaintext authentication requests on behalf of the SASL library. The service isolates all code requiring superuser privileges for SASL authentication into a single process, and can also be used to provide proxy authentication services to clients that do not understand SASL based authentication. The saslauthd service can be disabled with the following command:

# chkconfig saslauthd off

The saslauthd service provides essential functionality for performing authentication in some directory environments, such as those which use Kerberos and LDAP. For others, however, in which only local files may be consulted, it is not necessary and should be disabled.

Security identifiers

  • CCE-27263-3

Remediation script

                #
# Disable saslauthd for all run levels
#
chkconfig --level 0123456 saslauthd off

#
# Stop saslauthd if currently running
#
service saslauthd stop

              

Result for Disable SMART Disk Monitoring Service (smartd)

Result: pass

Rule ID: service_smartd_disabled

Time: 2014-07-16 17:33

Severity: low

SMART (Self-Monitoring, Analysis, and Reporting Technology) is a feature of hard drives that allows them to detect symptoms of disk failure and relay an appropriate warning. The smartd service can be disabled with the following command:

# chkconfig smartd off

SMART can help protect against denial of service due to failing hardware. Nevertheless, if it is not needed or the system's drives are not SMART-capable (such as solid state drives), it can be disabled.

Security identifiers

  • CCE-26853-2

Remediation script

                #
# Disable smartd for all run levels
#
chkconfig --level 0123456 smartd off

#
# Stop smartd if currently running
#
service smartd stop

              

Result for Disable System Statistics Reset Service (sysstat)

Result: pass

Rule ID: service_sysstat_disabled

Time: 2014-07-16 17:33

Severity: low

The sysstat service resets various I/O and CPU performance statistics to zero in order to begin counting from a fresh state at boot time. The sysstat service can be disabled with the following command:

# chkconfig sysstat off

By default the sysstat service merely runs a program at boot to reset the statistics, which can be retrieved using programs such as sar and sadc. These may provide useful insight into system operation, but unless used this service can be disabled.

Security identifiers

  • CCE-27265-8

Remediation script

                #
# Disable sysstat for all run levels
#
chkconfig --level 0123456 sysstat off

#
# Stop sysstat if currently running
#
service sysstat stop

              

Result for Enable cron Service

Result: pass

Rule ID: service_crond_enabled

Time: 2014-07-16 17:33

Severity: medium

The crond service is used to execute commands at preconfigured times. It is required by almost all systems to perform necessary maintenance tasks, such as notifying root of system activity. The crond service can be enabled with the following command:

# chkconfig --level 2345 crond on

Due to its usage for maintenance and security-supporting tasks, enabling the cron daemon is essential.

Security identifiers

  • CCE-27070-2

Remediation script

                #
# Enable crond for all run levels
#
chkconfig --level 0123456 crond on

#
# Start crond if not currently running
#
service crond start

              

Result for Disable anacron Service

Result: notchecked

Rule ID: disable_anacron

Time: 2014-07-16 17:33

Severity: low

The cronie-anacron package, which provides anacron functionality, is installed by default. The cronie-anacron package can be removed with the following command:

# yum erase cronie-anacron

The anacron service provides cron functionality for systems such as laptops and workstations that may be shut down during the normal times that cron jobs are scheduled to run. On systems which do not require this additional functionality, anacron could needlessly increase the possible attack surface for an intruder.

Security identifiers

  • CCE-27158-5

Result for Disable At Service (atd)

Result: pass

Rule ID: service_atd_disabled

Time: 2014-07-16 17:33

Severity: low

The at and batch commands can be used to schedule tasks that are meant to be executed only once. This allows delayed execution in a manner similar to cron, except that it is not recurring. The daemon atd keeps track of tasks scheduled via at and batch, and executes them at the specified time. The atd service can be disabled with the following command:

# chkconfig atd off

The atd service could be used by an unsophisticated insider to carry out activities outside of a normal login session, which could complicate accountability. Furthermore, the need to schedule tasks with at or batch is not common.

Security identifiers

  • CCE-27249-2

Remediation script

                #
# Disable atd for all run levels
#
chkconfig --level 0123456 atd off

#
# Stop atd if currently running
#
service atd stop

              

Result for Allow Only SSH Protocol 2

Result: pass

Rule ID: sshd_allow_only_protocol2

Time: 2014-07-16 17:33

Severity: high

Only SSH protocol version 2 connections should be permitted. The default setting in /etc/ssh/sshd_config is correct, and can be verified by ensuring that the following line appears:

Protocol 2

SSH protocol version 1 suffers from design flaws that result in security vulnerabilities and should not be used.

Security identifiers

  • CCE-27072-8

Result for Disable SSH Root Login

Result: pass

Rule ID: sshd_disable_root_login

Time: 2014-07-16 17:33

Severity: medium

The root user should never be allowed to login to a system directly over a network. To disable root login via SSH, add or correct the following line in /etc/ssh/sshd_config:

PermitRootLogin no

Permitting direct root login reduces auditable information about who ran privileged commands on the system and also allows direct attack attempts on root's password.

Security identifiers

  • CCE-27100-7

Remediation script

                grep -q ^PermitRootLogin /etc/ssh/sshd_config && \
  sed -i "s/PermitRootLogin.*/PermitRootLogin no/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
    echo "PermitRootLogin "no >> /etc/ssh/sshd_config
fi

              

Result for Use Only Approved Ciphers

Result: pass

Rule ID: sshd_use_approved_ciphers

Time: 2014-07-16 17:33

Severity: medium

Limit the ciphers to those algorithms which are FIPS-approved. Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode. The following line in /etc/ssh/sshd_config demonstrates use of FIPS-approved ciphers:

Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
The man page sshd_config(5) contains a list of supported ciphers.

Approved algorithms should impart some level of confidence in their implementation. These are also required for compliance.

Security identifiers

  • CCE-26555-3

Remediation script

                grep -q ^Ciphers /etc/ssh/sshd_config && \
  sed -i "s/Ciphers.*/Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
    echo "Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc" >> /etc/ssh/sshd_config
fi

              

Result for Disable X Windows Startup By Setting Runlevel

Result: pass

Rule ID: disable_xwindows_with_runlevel

Time: 2014-07-16 17:33

Severity: low

Setting the system's runlevel to 3 will prevent automatic startup of the X server. To do so, ensure the following line in /etc/inittab features a 3 as shown:

id:3:initdefault:

Unnecessary services should be disabled to decrease the attack surface of the system.

Security identifiers

  • CCE-27119-7

Result for Disable Avahi Server Software

Result: pass

Rule ID: disable_avahi

Time: 2014-07-16 17:33

Severity: low

The avahi-daemon service can be disabled with the following command:

# chkconfig avahi-daemon off

Because the Avahi daemon service keeps an open network port, it is subject to network attacks. Its functionality is convenient but is only appropriate if the local network can be trusted.

Security identifiers

  • CCE-27087-6

Result for Disable the CUPS Service

Result: pass

Rule ID: service_cups_disabled

Time: 2014-07-16 17:33

Severity: low

The cups service can be disabled with the following command:

# chkconfig cups off

Turn off unneeded services to reduce attack surface.

Security identifiers

  • CCE-26899-5

Remediation script

                #
# Disable cups for all run levels
#
chkconfig --level 0123456 cups off

#
# Stop cups if currently running
#
service cups stop

              

Result for Disable Print Server Capabilities

Result: pass

Rule ID: cups_disable_printserver

Time: 2014-07-16 17:33

Severity: low

To prevent remote users from potentially connecting to and using locally configured printers, disable the CUPS print server sharing capabilities. To do so, limit how the server will listen for print jobs by removing the more generic port directive from /etc/cups/cupsd.conf:

Port 631
and replacing it with the Listen directive:
Listen localhost:631
This will prevent remote users from printing to locally configured printers while still allowing local users on the machine to print normally.

By default, locally configured printers will not be shared over the network, but if this functionality has somehow been enabled, these recommendations will disable it again. Be sure to disable outgoing printer list broadcasts, or remote users will still be able to see the locally configured printers, even if they cannot actually print to them. To limit print serving to a particular set of users, use the Policy directive.

Security identifiers

  • CCE-27107-2

Result for Disable DHCP Service

Result: pass

Rule ID: disable_dhcp_server

Time: 2014-07-16 17:33

Severity: medium

The dhcpd service should be disabled on any system that does not need to act as a DHCP server. The dhcpd service can be disabled with the following command:

# chkconfig dhcpd off

Unmanaged or unintentionally activated DHCP servers may provide faulty information to clients, interfering with the operation of a legitimate site DHCP server if there is one.

Security identifiers

  • CCE-27074-4

Result for Uninstall DHCP Server Package

Result: pass

Rule ID: uninstall_dhcp_server

Time: 2014-07-16 17:33

Severity: medium

If the system does not need to act as a DHCP server, the dhcp package can be uninstalled. The dhcp package can be removed with the following command:

# yum erase dhcp

Removing the DHCP server ensures that it cannot be easily or accidentally reactivated and disrupt network operation.

Security identifiers

  • CCE-27120-5

Result for Do Not Use Dynamic DNS

Result: notchecked

Rule ID: dhcp_server_disable_ddns

Time: 2014-07-16 17:33

Severity: low

To prevent the DHCP server from receiving DNS information from clients, edit /etc/dhcp/dhcpd.conf, and add or correct the following global option:

ddns-update-style none;

The ddns-update-style option controls only whether the DHCP server will attempt to act as a Dynamic DNS client. As long as the DNS server itself is correctly configured to reject DDNS attempts, an incorrect ddns-update-style setting on the client is harmless (but should be fixed as a best practice).

The Dynamic DNS protocol is used to remotely update the data served by a DNS server. DHCP servers can use Dynamic DNS to publish information about their clients. This setup carries security risks, and its use is not recommended. If Dynamic DNS must be used despite the risks it poses, it is critical that Dynamic DNS transactions be protected using TSIG or some other cryptographic authentication mechanism. See dhcpd.conf(5) for more information about protecting the DHCP server from passing along malicious DNS data from its clients.

Security identifiers

  • CCE-27049-6

Result for Deny Decline Messages

Result: notchecked

Rule ID: dhcp_server_deny_decline

Time: 2014-07-16 17:33

Severity: low

Edit /etc/dhcp/dhcpd.conf and add or correct the following global option to prevent the DHCP server from responding the DHCPDECLINE messages, if possible:

deny declines;

The DHCPDECLINE message can be sent by a DHCP client to indicate that it does not consider the lease offered by the server to be valid. By issuing many DHCPDECLINE messages, a malicious client can exhaust the DHCP server's pool of IP addresses, causing the DHCP server to forget old address allocations.

Security identifiers

  • CCE-27106-4

Result for Deny BOOTP Queries

Result: notchecked

Rule ID: dhcp_server_deny_bootp

Time: 2014-07-16 17:33

Severity: low

Unless your network needs to support older BOOTP clients, disable support for the bootp protocol by adding or correcting the global option:

deny bootp;

The bootp option tells dhcpd to respond to BOOTP queries. If support for this simpler protocol is not needed, it should be disabled to remove attack vectors against the DHCP server.

Security identifiers

  • CCE-27077-7

Result for Disable DHCP Client

Result: pass

Rule ID: disable_dhcp_client

Time: 2014-07-16 17:33

Severity: low

For each interface on the system (e.g. eth0), edit /etc/sysconfig/network-scripts/ifcfg-interface and make the following changes:

  • Correct the BOOTPROTO line to read:

    BOOTPROTO=none

  • Add or correct the following lines, substituting the appropriate values based on your site's addressing scheme:

    NETMASK=255.255.255.0
    IPADDR=192.168.1.2
    GATEWAY=192.168.1.1

DHCP relies on trusting the local network. If the local network is not trusted, then it should not be used. However, the automatic configuration provided by DHCP is commonly used and the alternative, manual configuration, presents an unacceptable burden in many circumstances.

Security identifiers

  • CCE-27021-5

Result for Enable the NTP Daemon

Result: pass

Rule ID: service_ntpd_enabled

Time: 2014-07-16 17:33

Severity: medium

The ntpd service can be enabled with the following command:

# chkconfig --level 2345 ntpd on

Enabling the ntpd service ensures that the ntpd service will be running and that the system will synchronize its time to any servers specified. This is important whether the system is configured to be a client (and synchronize only its own clock) or it is also acting as an NTP server to other systems. Synchronizing time is essential for authentication services such as Kerberos, but it is also important for maintaining accurate logs and auditing possible security breaches.

The NTP daemon offers all of the functionality of ntpdate, which is now deprecated. Additional information on this is available at http://support.ntp.org/bin/view/Dev/DeprecatingNtpdate

Security identifiers

  • CCE-27093-4

Remediation script

                #
# Enable ntpd for all run levels
#
chkconfig --level 0123456 ntpd on

#
# Start ntpd if not currently running
#
service ntpd start

              

Result for Specify a Remote NTP Server

Result: pass

Rule ID: ntpd_specify_remote_server

Time: 2014-07-16 17:33

Severity: medium

To specify a remote NTP server for time synchronization, edit the file /etc/ntp.conf. Add or correct the following lines, substituting the IP or hostname of a remote NTP server for ntpserver:

server ntpserver
This instructs the NTP software to contact that remote server to obtain time data.

Synchronizing with an NTP server makes it possible to collate system logs from multiple sources or correlate computer events with real time events.

Security identifiers

  • CCE-27098-3

Result for Specify Additional Remote NTP Servers

Result: notchecked

Rule ID: ntpd_specify_multiple_servers

Time: 2014-07-16 17:33

Severity: low

Additional NTP servers can be specified for time synchronization in the file /etc/ntp.conf. To do so, add additional lines of the following form, substituting the IP address or hostname of a remote NTP server for ntpserver:

server ntpserver

Specifying additional NTP servers increases the availability of accurate time data, in the event that one of the specified servers becomes unavailable. This is typical for a system acting as an NTP server for other systems.

Security identifiers

  • CCE-26958-9

Result for Uninstall Sendmail Package

Result: pass

Rule ID: package_sendmail_removed

Time: 2014-07-16 17:33

Severity: medium

Sendmail is not the default mail transfer agent and is not installed by default. The sendmail package can be removed with the following command:

# yum erase sendmail

The sendmail software was not developed with security in mind and its design prevents it from being effectively contained by SELinux. Postfix should be used instead.

Security identifiers

  • CCE-27515-6

Result for Disable Postfix Network Listening

Result: pass

Rule ID: postfix_network_listening

Time: 2014-07-16 17:33

Severity: medium

Edit the file /etc/postfix/main.cf to ensure that only the following inet_interfaces line appears:

inet_interfaces = localhost

This ensures postfix accepts mail messages (such as cron job reports) from the local system only, and not from the network, which protects it from network attack.

Security identifiers

  • CCE-26780-7

Result for Configure LDAP Client to Use TLS For All Transactions

Result: pass

Rule ID: ldap_client_start_tls

Time: 2014-07-16 17:33

Severity: medium

Configure LDAP to enforce TLS use. First, edit the file /etc/pam_ldap.conf, and add or correct the following lines:

ssl start_tls
Then review the LDAP server and ensure TLS has been configured.

The ssl directive specifies whether to use ssl or not. If not specified it will default to no. It should be set to start_tls rather than doing LDAP over SSL.

Security identifiers

  • CCE-26690-8

Result for Configure Certificate Directives for LDAP Use of TLS

Result: pass

Rule ID: ldap_client_tls_cacertpath

Time: 2014-07-16 17:33

Severity: medium

Ensure a copy of a trusted CA certificate has been placed in the file /etc/pki/tls/CA/cacert.pem. Configure LDAP to enforce TLS use and to trust certificates signed by that CA. First, edit the file /etc/pam_ldap.conf, and add or correct either of the following lines:

tls_cacertdir /etc/pki/tls/CA
or
tls_cacertfile /etc/pki/tls/CA/cacert.pem
Then review the LDAP server and ensure TLS has been configured.

The tls_cacertdir or tls_cacertfile directives are required when tls_checkpeer is configured (which is the default for openldap versions 2.1 and up). These directives define the path to the trust certificates signed by the site CA.

Security identifiers

  • CCE-27189-0

Result for Uninstall openldap-servers Package

Result: pass

Rule ID: package_openldap-servers_removed

Time: 2014-07-16 17:33

Severity: low

The openldap-servers package should be removed if not in use. Is this machine the OpenLDAP server? If not, remove the package.

# yum erase openldap-servers
The openldap-servers RPM is not installed by default on RHEL 6 machines. It is needed only by the OpenLDAP server, not by the clients which use LDAP for authentication. If the system is not intended for use as an LDAP Server it should be removed.

Unnecessary packages should not be installed to decrease the attack surface of the system. While this software is clearly essential on an LDAP server, it is not necessary on typical desktop or workstation systems.

Security identifiers

  • CCE-26858-1

Result for Disable DNS Server

Result: pass

Rule ID: disable_dns_server

Time: 2014-07-16 17:33

Severity: low

The named service can be disabled with the following command:

# chkconfig named off

All network services involve some risk of compromise due to implementation flaws and should be disabled if possible.

Security identifiers

  • CCE-26873-0

Result for Uninstall bind Package

Result: pass

Rule ID: uninstall_bind

Time: 2014-07-16 17:33

Severity: low

To remove the bind package, which contains the named service, run the following command:

# yum erase bind

If there is no need to make DNS server software available, removing it provides a safeguard against its activation.

Security identifiers

  • CCE-27030-6

Result for Authenticate Zone Transfers

Result: notchecked

Rule ID: dns_server_authenticate_zone_transfers

Time: 2014-07-16 17:33

Severity: low

If it is necessary for a secondary nameserver to receive zone data via zone transfer from the primary server, follow the instructions here. Use dnssec-keygen to create a symmetric key file in the current directory:

# cd /tmp
# dnssec-keygen -a HMAC-MD5 -b 128 -n HOST dns.example.com
Kdns.example.com .+aaa +iiiii
This output is the name of a file containing the new key. Read the file to find the base64-encoded key string:
# cat Kdns.example.com .+NNN +MMMMM .key
dns.example.com IN KEY 512 3 157 base64-key-string
Add the directives to /etc/named.conf on the primary server:
key zone-transfer-key {
  algorithm hmac-md5;
  secret "base64-key-string ";
};
zone "example.com " IN {
  type master;
  allow-transfer { key zone-transfer-key; };
  ...
};
Add the directives below to /etc/named.conf on the secondary nameserver:
key zone-transfer-key {
  algorithm hmac-md5;
  secret "base64-key-string ";
};

server IP-OF-MASTER {
  keys { zone-transfer-key; };
};

zone "example.com " IN {
  type slave;
  masters { IP-OF-MASTER ; };
  ...
};

The purpose of the dnssec-keygen command is to create the shared secret string base64-key-string. Once this secret has been obtained and inserted into named.conf on the primary and secondary servers, the key files Kdns.example.com .+NNN +MMMMM .key and Kdns.example.com .+NNN +MMMMM .private are no longer needed, and may safely be deleted.

The BIND transaction signature (TSIG) functionality allows primary and secondary nameservers to use a shared secret to verify authorization to perform zone transfers. This method is more secure than using IP-based limiting to restrict nameserver access, since IP addresses can be easily spoofed. However, if you cannot configure TSIG between your servers because, for instance, the secondary nameserver is not under your control and its administrators are unwilling to configure TSIG, you can configure an allow-transfer directive with numerical IP addresses or ACLs as a last resort.

Security identifiers

  • CCE-27496-9

Result for Disable vsftpd Service

Result: pass

Rule ID: disable_vsftpd

Time: 2014-07-16 17:33

Severity: low

The vsftpd service can be disabled with the following command:

# chkconfig vsftpd off

Running FTP server software provides a network-based avenue of attack, and should be disabled if not needed. Furthermore, the FTP protocol is unencrypted and creates a risk of compromising sensitive information.

Security identifiers

  • CCE-26948-0

Remediation script

                if service vsftpd status >/dev/null; then
	service vsftpd stop
fi

              

Result for Uninstall vsftpd Package

Result: pass

Rule ID: uninstall_vsftpd

Time: 2014-07-16 17:33

Severity: low

The vsftpd package can be removed with the following command:

# yum erase vsftpd

Removing the vsftpd package decreases the risk of its accidental activation.

Security identifiers

  • CCE-26687-4

Result for Set httpd ServerTokens Directive to Prod

Result: notchecked

Rule ID: httpd_servertokens_prod

Time: 2014-07-16 17:33

Severity: low

ServerTokens Prod restricts information in page headers, returning only the word "Apache."

Add or correct the following directive in /etc/httpd/conf/httpd.conf:

ServerTokens Prod

Information disclosed to clients about the configuration of the web server and system could be used to plan an attack on the given system. This information disclosure should be restricted to a minimum.

Security identifiers

  • CCE-27425-8

Result for Set Permissions on the /var/log/httpd/ Directory

Result: pass

Rule ID: httpd_logs_permissions

Time: 2014-07-16 17:33

Severity: low

Ensure that the permissions on the web server log directory is set to 700:

# chmod 700 /var/log/httpd/
This is its default setting.

Access to the web server's log files may allow an unauthorized user or attacker to access information about the web server or alter the server's log files.

Security identifiers

  • CCE-27150-2

Result for Set Permissions on All Configuration Files Inside /etc/httpd/conf/

Result: pass

Rule ID: httpd_conf_files_permissions

Time: 2014-07-16 17:33

Severity: low

Set permissions on the web server configuration files to 640:

# chmod 640 /etc/httpd/conf/*

Access to the web server's configuration files may allow an unauthorized user or attacker to access information about the web server or to alter the server's configuration files.

Security identifiers

  • CCE-27316-9