Introduction

Test Result

Result ID Profile Start time End time Benchmark Benchmark version
xccdf_org.open-scap_testresult_stig-rhel6-server stig-rhel6-server 2013-09-27 19:03 2013-09-27 19:03 embedded 0.9

Target info

Targets

  • localhost.localdomain

Addresses

  • 127.0.0.1
  • 192.168.122.90
  • ::1
  • fe80::5054:ff:fe59:eba4

Platforms

  • cpe:/o:redhat:enterprise_linux:6
  • cpe:/o:redhat:enterprise_linux:6::client

Score

system score max % bar
urn:xccdf:scoring:default 70.35 100.00 70.35%

Results overview

Rule Results Summary

pass fixed fail error not selected not checked not applicable informational unknown total
103 0 92 1 162 24 0 0 3 385
Title Result
Ensure /tmp Located On Separate Partition pass
Ensure /var Located On Separate Partition pass
Ensure /var/log Located On Separate Partition pass
Ensure /var/log/audit Located On Separate Partition pass
Ensure /home Located On Separate Partition pass
Encrypt Partitions notchecked
Ensure Red Hat GPG Key Installed pass
Ensure gpgcheck Enabled In Main Yum Configuration pass
Ensure gpgcheck Enabled For All Yum Package Repositories pass
Ensure Software Patches Installed notchecked
Install AIDE pass
Configure Periodic Execution of AIDE notchecked
Verify File Permissions with RPM fail
Verify File Hashes with RPM pass
Install Intrusion Detection Software notchecked
Install Virus Scanning Software notchecked
Add noexec Option to Removable Media Partitions fail
Disable Modprobe Loading of USB Storage Driver fail
Disable the Automounter 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 notchecked
Verify that System Executables Have Root Ownership notchecked
Verify that All World-Writable Directories Have Sticky Bits Set pass
Ensure No World-Writable Files Exist notchecked
Ensure All Files Are Owned by a User pass
Ensure All Files Are Owned by a Group pass
Ensure All World-Writable Directories Are Owned by a System Account pass
Set Daemon Umask fail
Disable Core Dumps for All Users fail
Enable ExecShield pass
Enable Randomized Layout of Virtual Address Space pass
Ensure SELinux Not Disabled in /etc/grub.conf pass
Ensure SELinux State is Enforcing pass
Configure SELinux Policy pass
Ensure No Device Files are Unlabeled by SELinux error
Restrict Virtual Console Root Logins fail
Restrict Serial Port Root Logins pass
Ensure that System Accounts Do Not Run a Shell Upon Login notchecked
Verify Only Root Has UID 0 pass
Prevent Log In to Accounts With Empty Password fail
Verify All Account Password Hashes are Shadowed pass
All GIDs referenced in /etc/passwd must be defined in /etc/group notchecked
Verify No netrc Files Exist pass
Set Password Minimum Length in login.defs fail
Set Password Minimum Age fail
Set Password Maximum Age fail
Set Password Warning Age pass
Set Account Expiration Following Inactivity fail
Ensure All Accounts on the System Have Unique Names notchecked
Assign Expiration Date to Temporary Accounts notchecked
Set Last Logon/Access Notification fail
Set Password Retry Prompts Permitted Per-Session pass
Set Password to Maximum of Three Consecutive Repeating Characters notchecked
Set Password Strength Minimum Digit Characters fail
Set Password Strength Minimum Uppercase Characters fail
Set Password Strength Minimum Special Characters fail
Set Password Strength Minimum Lowercase Characters fail
Set Password Strength Minimum Different Characters fail
Set Deny For Failed Password Attempts fail
Set Lockout Time For Failed Password Attempts notchecked
Set Interval For Counting Failed Password Attempts notchecked
Limit Password Reuse fail
Set Password Hashing Algorithm in /etc/pam.d/system-auth fail
Set Password Hashing Algorithm in /etc/login.defs fail
Set Password Hashing Algorithm in /etc/libuser.conf fail
Limit the Number of Concurrent Login Sessions Allowed Per User fail
Ensure the Default Bash Umask is Set Correctly fail
Ensure the Default C Shell Umask is Set Correctly fail
Ensure the Default Umask is Set Correctly in /etc/profile fail
Ensure the Default Umask is Set Correctly in login.defs pass
Verify /etc/grub.conf User Ownership pass
Verify /etc/grub.conf Group Ownership pass
Verify /boot/grub/grub.conf Permissions pass
Set Boot Loader Password fail
Require Authentication for Single User Mode fail
Disable Ctrl-Alt-Del Reboot Activation notchecked
Disable Interactive Boot fail
Set GNOME Login Inactivity Timeout fail
GNOME Desktop Screensaver Mandatory Use fail
Enable Screen Lock Activation After Idle Period fail
Implement Blank Screen Saver fail
Install the screen Package pass
Enable Smart Card Login notchecked
Modify the System Login Banner fail
Enable GUI Warning Banner fail
Set GUI Warning Banner Text notchecked
Disable Kernel Parameter for Sending ICMP Redirects by Default fail
Disable Kernel Parameter for Sending ICMP Redirects for All Interfaces fail
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 fail
Disable Kernel Parameter for Accepting Secure Redirects for All Interfaces fail
Enable Kernel Parameter to Log Martian Packets fail
Disable Kernel Parameter for Accepting Source-Routed Packets By Default fail
Disable Kernel Parameter for Accepting ICMP Redirects By Default fail
Disable Kernel Parameter for Accepting Secure Redirects By Default fail
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 fail
Enable Kernel Parameter to Use Reverse Path Filtering for All Interfaces fail
Enable Kernel Parameter to Use Reverse Path Filtering by Default fail
Disable Bluetooth Service pass
Disable Bluetooth Kernel Modules fail
Disable IPv6 Networking Support Automatic Loading fail
Disable Accepting IPv6 Redirects fail
Verify ip6tables Enabled if Using IPv6 pass
Verify iptables Enabled pass
Set Default iptables Policy for Incoming Packets fail
Set Default iptables Policy for Forwarded Packets notchecked
Disable DCCP Support fail
Disable SCTP Support fail
Disable RDS Support fail
Disable TIPC Support fail
Install openswan Package pass
Ensure rsyslog is Installed pass
Enable rsyslog Service pass
Ensure Log Files Are Owned By Appropriate User pass
Ensure Log Files Are Owned By Appropriate Group unknown
Ensure System Log Files Have Correct Permissions unknown
Ensure Logs Sent To Remote Host fail
Ensure Logrotate Runs Periodically unknown
Enable auditd Service pass
Enable Auditing for Processes Which Start Prior to the Audit Daemon fail
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 fail
Configure auditd admin_space_left Action on Low Disk Space fail
Configure auditd mail_acct Action on Low Disk Space pass
Record attempts to alter time through adjtimex fail
Record attempts to alter time through settimeofday fail
Record Attempts to Alter Time Through stime pass
Record Attempts to Alter Time Through clock_settime fail
Record Attempts to Alter the localtime File fail
Record Events that Modify User/Group Information fail
Record Events that Modify the System's Network Environment fail
System Audit Logs Must Have Mode 0640 or Less Permissive pass
Record Events that Modify the System's Mandatory Access Controls fail
Record Events that Modify the System's Discretionary Access Controls - chmod fail
Record Events that Modify the System's Discretionary Access Controls - chown fail
Record Events that Modify the System's Discretionary Access Controls - fchmod fail
Record Events that Modify the System's Discretionary Access Controls - fchmodat fail
Record Events that Modify the System's Discretionary Access Controls - fchown fail
Record Events that Modify the System's Discretionary Access Controls - fchownat fail
Record Events that Modify the System's Discretionary Access Controls - fremovexattr fail
Record Events that Modify the System's Discretionary Access Controls - fsetxattr fail
Record Events that Modify the System's Discretionary Access Controls - lchown fail
Record Events that Modify the System's Discretionary Access Controls - lremovexattr fail
Record Events that Modify the System's Discretionary Access Controls - lsetxattr fail
Record Events that Modify the System's Discretionary Access Controls - removexattr fail
Record Events that Modify the System's Discretionary Access Controls - setxattr fail
Ensure auditd Collects Unauthorized Access Attempts to Files (unsuccessful) fail
Ensure auditd Collects Information on the Use of Privileged Commands fail
Ensure auditd Collects Information on Exporting to Media (successful) fail
Ensure auditd Collects File Deletion Events by User fail
Ensure auditd Collects System Administrator Actions fail
Ensure auditd Collects Information on Kernel Module Loading and Unloading fail
Disable xinetd Service pass
Uninstall xinetd Package pass
Disable telnet Service fail
Uninstall telnet-server Package pass
Uninstall rsh-server Package pass
Disable rexec Service pass
Disable rsh Service pass
Disable rlogin Service pass
Remove Rsh Trust Files 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 Network Console (netconsole) pass
Disable ntpdate Service (ntpdate) pass
Disable Odd Job Daemon (oddjobd) pass
Disable Apache Qpid (qpidd) pass
Disable Network Router Discovery Daemon (rdisc) pass
Disable Red Hat Network Service (rhnsd) fail
Enable cron Service pass
Allow Only SSH Protocol 2 pass
Set SSH Idle Timeout Interval fail
Set SSH Client Alive Count fail
Disable SSH Support for .rhosts Files pass
Disable Host-Based Authentication pass
Disable SSH Root Login pass
Disable SSH Access via Empty Passwords fail
Enable SSH Warning Banner fail
Do Not Allow SSH Environment Options fail
Use Only Approved Ciphers fail
Disable X Windows Startup By Setting Runlevel pass
Remove the X Windows Package Group pass
Disable Avahi Server Software pass
Disable DHCP Client pass
Enable the NTP Daemon pass
Specify a Remote NTP Server pass
Enable Postfix Service pass
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
Mount Remote Filesystems with nodev pass
Mount Remote Filesystems with nosuid pass
Ensure Insecure File Locking is Not Allowed notchecked
Enable Logging of All FTP Transactions notchecked
Create Warning Banners for All FTP Users notchecked
Require Client SMB Packet Signing, if using smbclient pass
Require Client SMB Packet Signing, if using mount.cifs pass
Configure SNMP Service to Use Only SNMPv3 or Newer notchecked
Ensure Default Password Is Not Used notchecked

Results details

Result for Ensure /tmp Located On Separate Partition

Result: pass

Rule ID: partition_for_tmp

Time: 2013-09-27 19:03

Severity: low

The /tmp directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.

The /tmp partition is used as temporary storage by many programs. Placing /tmp in its own partition enables the setting of more restrictive mount options, which can help protect programs which use it.

Security identifiers

  • CCE-26435-8

Result for Ensure /var Located On Separate Partition

Result: pass

Rule ID: partition_for_var

Time: 2013-09-27 19:03

Severity: low

The /var directory is used by daemons and other system services to store frequently-changing data. Ensure that /var has its own partition or logical volume at installation time, or migrate it using LVM.

Ensuring that /var is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the /var directory to contain world-writable directories, installed by other software packages.

Security identifiers

  • CCE-26639-5

Result for Ensure /var/log Located On Separate Partition

Result: pass

Rule ID: partition_for_var_log

Time: 2013-09-27 19:03

Severity: low

System logs are stored in the /var/log directory. Ensure that it has its own partition or logical volume at installation time, or migrate it using LVM.

Placing /var/log in its own partition enables better separation between log files and other files in /var/.

Security identifiers

  • CCE-26215-4

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

Result: pass

Rule ID: partition_for_var_log_audit

Time: 2013-09-27 19:03

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 Ensure /home Located On Separate Partition

Result: pass

Rule ID: partition_for_home

Time: 2013-09-27 19:03

Severity: low

If user home directories will be stored locally, create a separate partition for /home at installation time (or migrate it later using LVM). If /home will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later.

Ensuring that /home is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage.

Security identifiers

  • CCE-26557-9

Result for Encrypt Partitions

Result: notchecked

Rule ID: encrypt_partitions

Time: 2013-09-27 19:03

Severity: low

Red Hat Enterprise Linux 6 natively supports partition encryption through the Linux Unified Key Setup-on-disk-format (LUKS) technology. The easiest way to encrypt a partition is during installation time.

For manual installations, select the Encrypt checkbox during partition creation to encrypt the partition. When this option is selected the system will prompt for a passphrase to use in decrypting the partition. The passphrase will subsequently need to be entered manually every time the system boots.

For automated/unattended installations, it is possible to use Kickstart by adding the --encrypted and --passphrase= options to the definition of each partition to be encrypted. For example, the following line would encrypt the root partition:

part / --fstype=ext3 --size=100 --onpart=hda1 --encrypted --passphrase=PASSPHRASE
Any PASSPHRASE is stored in the Kickstart in plaintext, and the Kickstart must then be protected accordingly. Omitting the --passphrase= option from the partition definition will cause the installer to pause and interactively ask for the passphrase during installation.

Detailed information on encrypting partitions using LUKS can be found on the Red Had Documentation web site:
https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Security_Guide/sect-Security_Guide-LUKS_Disk_Encryption.html

The risk of a system's physical compromise, particularly mobile systems such as laptops, places its data at risk of compromise. Encrypting this data mitigates the risk of its loss if the system is lost.

Result for Ensure Red Hat GPG Key Installed

Result: pass

Rule ID: ensure_redhat_gpgkey_installed

Time: 2013-09-27 19:03

Severity: high

To ensure the system can cryptographically verify base software packages come from Red Hat (and to connect to the Red Hat Network to receive them if desired), the Red Hat GPG key must properly be installed. To ensure the GPG key is installed, run:

# rhn_register
If the system is not connected to the internet, or a local RHN Satellite, then install the Red Hat GPG key from a secure, static location, such as the Red Hat installation CD-ROM or DVD. Assuming the disc is mounted in /mnt/cdrom, use the following command as the root user to import it into the keyring:
# rpm --import /mnt/cdrom/RPM-GPG-KEY

This key is necessary to cryptographically verify packages are from Red Hat.

Security identifiers

  • CCE-26506-6

Result for Ensure gpgcheck Enabled In Main Yum Configuration

Result: pass

Rule ID: ensure_gpgcheck_globally_activated

Time: 2013-09-27 19:03

Severity: high

The gpgcheck option should be used to ensure checking of an RPM package's signature always occurs prior to its installation. To configure yum to check package signatures before installing them, ensure the following line appears in /etc/yum.conf in the [main] section:

gpgcheck=1

Ensuring the validity of packages' cryptographic signatures prior to installation ensures the provenance of the software and protects against malicious tampering.

Security identifiers

  • CCE-26709-6

Result for Ensure gpgcheck Enabled For All Yum Package Repositories

Result: pass

Rule ID: ensure_gpgcheck_never_disabled

Time: 2013-09-27 19:03

Severity: high

To ensure signature checking is not disabled for any repos, remove any lines from files in /etc/yum.repos.d of the form:

gpgcheck=0

Ensuring all packages' cryptographic signatures are valid prior to installation ensures the provenance of the software and protects against malicious tampering.

Security identifiers

  • CCE-26647-8

Result for Ensure Software Patches Installed

Result: notchecked

Rule ID: security_patches_up_to_date

Time: 2013-09-27 19:03

Severity: high

If the system is joined to the Red Hat Network, a Red Hat Satellite Server, or a yum server, run the following command to install updates:

# yum update
If the system is not configured to use one of these sources, updates (in the form of RPM packages) can be manually downloaded from the Red Hat Network and installed using rpm.

Installing software updates is a fundamental mitigation against the exploitation of publicly-known vulnerabilities.

Result for Install AIDE

Result: pass

Rule ID: package_aide_installed

Time: 2013-09-27 19:03

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 Configure Periodic Execution of AIDE

Result: notchecked

Rule ID: aide_periodic_cron_checking

Time: 2013-09-27 19:03

Severity: medium

AIDE should be executed on a periodic basis to check for changes. 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 may reveal unexpected changes in installed files.

Security identifiers

  • CCE-27222-9

Result for Verify File Permissions with RPM

Result: fail

Rule ID: rpm_verify_permissions

Time: 2013-09-27 19:03

Severity: low

The RPM package management system can check file access permissions of installed software packages, including many that are important to system security. The following command will reset permissions to their expected values:

# rpm --setperms package

Permissions on system binaries and configuration files that are too generous could allow an unauthorized user to gain privileges that they should not have. The permissions set by the vendor should be maintained. Any deviations from this baseline should be investigated.

Security identifiers

  • CCE-26731-0

Result for Verify File Hashes with RPM

Result: pass

Rule ID: rpm_verify_hashes

Time: 2013-09-27 19:03

Severity: low

The RPM package management system can check the hashes of installed software packages, including many that are important to system security. Run the following command to list which files on the system have hashes that differ from what is expected by the RPM database:

# rpm -Va | grep '^..5'
A "c" in the second column indicates that a file is a configuration file, which may appropriately be expected to change. If the file that has changed was not expected to then refresh from distribution media or online repositories.
rpm -Uvh affected_package
OR
yum reinstall affected_package

The hash on important files like system executables should match the information given by the RPM database. Executables with erroneous hashes could be a sign of nefarious activity on the system.

Security identifiers

  • CCE-27223-7

Result for Install Intrusion Detection Software

Result: notchecked

Rule ID: install_hids

Time: 2013-09-27 19:03

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.

Install an additional intrusion detection tool to provide complementary or duplicative monitoring, reporting, and reaction capabilities to those of the base platform. For DoD systems, the McAfee Host Based Security System is provided to fulfill this role.

Adding host-based intrusion detection tools can provide the capability to automatically take actions in response to malicious behavior, which can provide additional agility in reacting to network threats. These tools also often include a reporting capability to provide network awareness of system, which may not otherwise exist in an organization's systems management regime.

Result for Install Virus Scanning Software

Result: notchecked

Rule ID: install_antivirus

Time: 2013-09-27 19:03

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.

Result for Add noexec Option to Removable Media Partitions

Result: fail

Rule ID: mountopt_noexec_on_removable_partitions

Time: 2013-09-27 19:03

Severity: low

The noexec mount option prevents the direct execution of binaries on the mounted filesystem. Users should not be allowed to execute binaries that exist on partitions mounted from removable media (such as a USB key). The noexec option prevents code from being executed directly from the media itself, and may therefore provide a line of defense against certain types of worms or malicious code. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of any removable media partitions.

Allowing users to execute binaries from removable media such as USB keys exposes the system to potential compromise.

Security identifiers

  • CCE-27196-5

Result for Disable Modprobe Loading of USB Storage Driver

Result: fail

Rule ID: kernel_module_usb-storage_disabled

Time: 2013-09-27 19:03

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 unauthorized software and other vulnerabilities. Support for these devices should be disabled and the devices themselves should be tightly controlled.

Security identifiers

  • CCE-27016-5

Result for Disable the Automounter

Result: pass

Rule ID: service_autofs_disabled

Time: 2013-09-27 19:03

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 is almost always possible to configure filesystem mounts statically by editing /etc/fstab rather than relying on the automounter.

If the autofs service is not needed to dynamically mount NFS filesystems or removable media, disable the service for all runlevels:

# chkconfig --level 0123456 autofs off
Stop the service if it is already running:
# service autofs stop

All filesystems that are required for the successful operation of the system should be explicitly listed in /etc/fstab by and administrator. New filesystems should not be arbitrarily introduced via the automounter.

Security identifiers

  • CCE-26976-1

Result for Verify User Who Owns shadow File

Result: pass

Rule ID: userowner_shadow_file

Time: 2013-09-27 19:03

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

Result for Verify Group Who Owns shadow File

Result: pass

Rule ID: groupowner_shadow_file

Time: 2013-09-27 19:03

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

Result for Verify Permissions on shadow File

Result: pass

Rule ID: perms_shadow_file

Time: 2013-09-27 19:03

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

Result for Verify User Who Owns group File

Result: pass

Rule ID: userowner_group_file

Time: 2013-09-27 19:03

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: groupowner_group_file

Time: 2013-09-27 19:03

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: perms_group_file

Time: 2013-09-27 19:03

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: userowner_gshadow_file

Time: 2013-09-27 19:03

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: groupowner_gshadow_file

Time: 2013-09-27 19:03

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: perms_gshadow_file

Time: 2013-09-27 19:03

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: userowner_passwd_file

Time: 2013-09-27 19:03

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: groupowner_passwd_file

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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.

Result for Verify that Shared Library Files Have Root Ownership

Result: pass

Rule ID: file_ownership_library_dirs

Time: 2013-09-27 19:03

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 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.

Result for Verify that System Executables Have Restrictive Permissions

Result: notchecked

Rule ID: file_permissions_binary_dirs

Time: 2013-09-27 19:03

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.

Result for Verify that System Executables Have Root Ownership

Result: notchecked

Rule ID: file_ownership_binary_dirs

Time: 2013-09-27 19:03

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.

Result for Verify that All World-Writable Directories Have Sticky Bits Set

Result: pass

Rule ID: sticky_world_writable_dirs

Time: 2013-09-27 19:03

Severity: low

When the so-called 'sticky bit' is set on a directory, only the owner of a given file may remove that file from the directory. Without the sticky bit, any user with write access to a directory may remove any file in the directory. Setting the sticky bit prevents users from removing each other's files. In cases where there is no reason for a directory to be world-writable, a better solution is to remove that permission rather than to set the sticky bit. However, if a directory is used by a particular application, consult that application's documentation instead of blindly changing modes.
To set the sticky bit on a world-writable directory DIR, run the following command:

# chmod +t DIR

Failing to set the sticky bit on public directories allows unauthorized users to delete files in the directory structure.

The only authorized public directories are those temporary directories supplied with the system, or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system, by users for temporary file storage (such as /tmp), and for directories requiring global read/write access.

Security identifiers

  • CCE-26840-9

Result for Ensure No World-Writable Files Exist

Result: notchecked

Rule ID: world_writeable_files

Time: 2013-09-27 19:03

Severity: medium

It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account.

Data in world-writable files can be modified by any user on the system. In almost all circumstances, files can be configured using a combination of user and group permissions to support whatever legitimate access is needed without the risk caused by world-writable files.

Security identifiers

  • CCE-26910-0

Result for Ensure All Files Are Owned by a User

Result: pass

Rule ID: no_files_unowned_by_user

Time: 2013-09-27 19:03

Severity: low

If any files are not owned by a user, then the cause of their lack of ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate user.

Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.

Security identifiers

  • CCE-27032-2

Result for Ensure All Files Are Owned by a Group

Result: pass

Rule ID: no_files_unowned_by_group

Time: 2013-09-27 19:03

Severity: low

If any files are not owned by a group, then the cause of their lack of group-ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate group.

Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.

Security identifiers

  • CCE-26872-2

Result for Ensure All World-Writable Directories Are Owned by a System Account

Result: pass

Rule ID: world_writable_files_system_ownership

Time: 2013-09-27 19:03

Severity: low

All directories in local partitions which are world-writable should be owned by root or another system account. If any world-writable directories are not owned by a system account, this should be investigated. Following this, the files should be deleted or assigned to an appropriate group.

Allowing a user account to own a world-writable directory is undesirable because it allows the owner of that directory to remove or replace any files that may be placed in the directory by other users.

Security identifiers

  • CCE-26642-9

Result for Set Daemon Umask

Result: fail

Rule ID: set_daemon_umask

Time: 2013-09-27 19:03

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

Result for Disable Core Dumps for All Users

Result: fail

Rule ID: disable_users_coredumps

Time: 2013-09-27 19:03

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

Result for Enable ExecShield

Result: pass

Rule ID: enable_execshield

Time: 2013-09-27 19:03

Severity: medium

To set the runtime status of the kernel.exec-shield kernel parameter, run the following command:

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

ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places a process's memory regions such as the stack and heap higher than this address, the hardware prevents execution in that address range.

Security identifiers

  • CCE-27007-4

Result for Enable Randomized Layout of Virtual Address Space

Result: pass

Rule ID: enable_randomize_va_space

Time: 2013-09-27 19:03

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

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

Result: pass

Rule ID: enable_selinux_bootloader

Time: 2013-09-27 19:03

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

Result for Ensure SELinux State is Enforcing

Result: pass

Rule ID: set_selinux_state

Time: 2013-09-27 19:03

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

Result for Configure SELinux Policy

Result: pass

Rule ID: set_selinux_policy

Time: 2013-09-27 19:03

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

Result for Ensure No Device Files are Unlabeled by SELinux

Result: error

Rule ID: selinux_unlabeled_device_files

Time: 2013-09-27 19:03

Severity: low

Device files, which are used for communication with important system resources, should be labeled with proper SELinux types. If any device files carry the SELinux type unlabeled_t, investigate the cause and correct the file's context.

If a device file carries the SELinux type unlabeled_t, then SELinux cannot properly restrict access to the device file.

Security identifiers

  • CCE-26774-0

Result for Restrict Virtual Console Root Logins

Result: fail

Rule ID: restrict_root_console_logins

Time: 2013-09-27 19:03

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

Result for Restrict Serial Port Root Logins

Result: pass

Rule ID: restrict_serial_port_logins

Time: 2013-09-27 19:03

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 Ensure that System Accounts Do Not Run a Shell Upon Login

Result: notchecked

Rule ID: no_shelllogin_for_systemaccounts

Time: 2013-09-27 19:03

Severity: medium

Some accounts are not associated with a human user of the system, and exist to perform some administrative function. Should an attacker be able to log into these accounts, they should not be granted access to a shell.

The login shell for each local account is stored in the last field of each line in /etc/passwd. System accounts are those user accounts with a user ID less than 500. The user ID is stored in the third field. If any system account SYSACCT (other than root) has a login shell, disable it with the command:

# usermod -s /sbin/nologin SYSACCT

Do not perform the steps in this section on the root account. Doing so might cause the system to become inaccessible.

Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts.

Security identifiers

  • CCE-26966-2

Result for Verify Only Root Has UID 0

Result: pass

Rule ID: no_uidzero_except_root

Time: 2013-09-27 19:03

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

Result for Prevent Log In to Accounts With Empty Password

Result: fail

Rule ID: no_empty_passwords

Time: 2013-09-27 19:03

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

Result for Verify All Account Password Hashes are Shadowed

Result: pass

Rule ID: no_hashes_outside_shadow

Time: 2013-09-27 19:03

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 All GIDs referenced in /etc/passwd must be defined in /etc/group

Result: notchecked

Rule ID: gid_passwd_group_same

Time: 2013-09-27 19:03

Severity: low

Add a group to the system for each GID referenced without a corresponding group.

Inconsistency in GIDs between /etc/passwd and /etc/group could lead to a user having unintended rights.

Result for Verify No netrc Files Exist

Result: pass

Rule ID: no_netrc_files

Time: 2013-09-27 19:03

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: fail

Rule ID: password_min_len

Time: 2013-09-27 19:03

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

Result for Set Password Minimum Age

Result: fail

Rule ID: password_min_age

Time: 2013-09-27 19:03

Severity: medium

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

PASS_MIN_DAYS DAYS
A value of 1 day is considered for sufficient for many environments. The DoD requirement is 1.

Setting the minimum password age protects against users cycling back to a favorite password after satisfying the password reuse requirement.

Security identifiers

  • CCE-27013-2

Result for Set Password Maximum Age

Result: fail

Rule ID: password_max_age

Time: 2013-09-27 19:03

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

Result for Set Password Warning Age

Result: pass

Rule ID: password_warn_age

Time: 2013-09-27 19:03

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

Result for Set Account Expiration Following Inactivity

Result: fail

Rule ID: account_disable_post_pw_expiration

Time: 2013-09-27 19:03

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

Result for Ensure All Accounts on the System Have Unique Names

Result: notchecked

Rule ID: account_unique_name

Time: 2013-09-27 19:03

Severity: low

Change usernames, or delete accounts, so each has a unique name.

Unique usernames allow for accountability on the system.

Security identifiers

  • CCE-27609-7

Result for Assign Expiration Date to Temporary Accounts

Result: notchecked

Rule ID: account_temp_expire_date

Time: 2013-09-27 19:03

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.

Result for Set Last Logon/Access Notification

Result: fail

Rule ID: display_login_attempts

Time: 2013-09-27 19:03

Severity: low

To configure the system to notify users of last logon/access using pam_lastlog, add the following line immediately after session required pam_limits.so:

session       required     pam_lastlog.so showfailed

Users need to be aware of activity that occurs regarding their account. Providing users with information regarding the number of unsuccessful attempts that were made to login to their account allows the user to determine if any unauthorized activity has occurred and gives them an opportunity to notify administrators.

Security identifiers

  • CCE-27291-4

Result for Set Password Retry Prompts Permitted Per-Session

Result: pass

Rule ID: password_retry

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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: fail

Rule ID: password_require_digits

Time: 2013-09-27 19:03

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: fail

Rule ID: password_require_uppercases

Time: 2013-09-27 19:03

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: fail

Rule ID: password_require_specials

Time: 2013-09-27 19:03

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: fail

Rule ID: password_require_lowercases

Time: 2013-09-27 19:03

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: fail

Rule ID: password_require_diffchars

Time: 2013-09-27 19:03

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 Set Deny For Failed Password Attempts

Result: fail

Rule ID: deny_password_attempts

Time: 2013-09-27 19:03

Severity: medium

To configure the system to lock out accounts after a number of incorrect login attempts using pam_faillock.so:

Add the following lines immediately below the pam_unix.so statement in AUTH section of /etc/pam.d/system-auth:

auth [default=die] pam_faillock.so authfail deny=3 unlock_time=604800 fail_interval=900
auth required pam_faillock.so authsucc deny=3 unlock_time=604800 fail_interval=900

Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks.

Security identifiers

  • CCE-26844-1

Result for Set Lockout Time For Failed Password Attempts

Result: notchecked

Rule ID: deny_password_attempts_unlock_time

Time: 2013-09-27 19:03

Severity: medium

To configure the system to lock out accounts after a number of incorrect login attempts and require an administrator to unlock the account using pam_faillock.so:

Add the following lines immediately below the pam_env.so statement in /etc/pam.d/system-auth:

auth [default=die] pam_faillock.so authfail deny=3 unlock_time=604800 fail_interval=900
auth required pam_faillock.so authsucc deny=3 unlock_time=604800 fail_interval=900

Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks. Ensuring that an administrator is involved in unlocking locked accounts draws appropriate attention to such situations.

Security identifiers

  • CCE-27110-6

Result for Set Interval For Counting Failed Password Attempts

Result: notchecked

Rule ID: deny_password_attempts_fail_interval

Time: 2013-09-27 19:03

Severity: medium

To configure the system to lock out accounts after a number of incorrect login attempts within a 15 minute interval using pam_faillock.so:

Add the following lines immediately below the pam_env.so statement in /etc/pam.d/system-auth:

auth [default=die] pam_faillock.so authfail deny=3 unlock_time=604800 fail_interval=900
auth required pam_faillock.so authsucc deny=3 unlock_time=604800 fail_interval=900

Locking out user accounts after a number of incorrect attempts within a specific period of time prevents direct password guessing attacks.

Security identifiers

  • CCE-27215-3

Result for Limit Password Reuse

Result: fail

Rule ID: limiting_password_reuse

Time: 2013-09-27 19:03

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/pam.d/system-auth

Result: fail

Rule ID: set_password_hashing_algorithm_systemauth

Time: 2013-09-27 19:03

Severity: medium

In /etc/pam.d/system-auth, the password section of the file controls which PAM modules execute during a password change. Set the pam_unix.so module in the password section to include the argument sha512, as shown below:

password    sufficient    pam_unix.so sha512 other arguments...
This will help ensure when local users change their passwords, hashes for the new passwords will be generated using the SHA-512 algorithm. This is the default.

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

Security identifiers

  • CCE-26303-8

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

Result: fail

Rule ID: set_password_hashing_algorithm_logindefs

Time: 2013-09-27 19:03

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: fail

Rule ID: set_password_hashing_algorithm_libuserconf

Time: 2013-09-27 19:03

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: fail

Rule ID: max_concurrent_login_sessions

Time: 2013-09-27 19:03

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

Result for Ensure the Default Bash Umask is Set Correctly

Result: fail

Rule ID: user_umask_bashrc

Time: 2013-09-27 19:03

Severity: low

To ensure the default umask for users of the Bash shell is set properly, add or correct the umask setting in /etc/bashrc to read as follows:

umask 077

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Security identifiers

  • CCE-26917-5

Result for Ensure the Default C Shell Umask is Set Correctly

Result: fail

Rule ID: user_umask_cshrc

Time: 2013-09-27 19:03

Severity: low

To ensure the default umask for users of the C shell is set properly, add or correct the umask setting in /etc/csh.cshrc to read as follows:

umask 077

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Security identifiers

  • CCE-27034-8

Result for Ensure the Default Umask is Set Correctly in /etc/profile

Result: fail

Rule ID: user_umask_profile

Time: 2013-09-27 19:03

Severity: low

To ensure the default umask controlled by /etc/profile is set properly, add or correct the umask setting in /etc/profile to read as follows:

umask 077

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Security identifiers

  • CCE-26669-2

Result for Ensure the Default Umask is Set Correctly in login.defs

Result: pass

Rule ID: user_umask_logindefs

Time: 2013-09-27 19:03

Severity: low

To ensure the default umask controlled by /etc/login.defs is set properly, add or correct the UMASK setting in /etc/login.defs to read as follows:

UMASK 077

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read and written to by unauthorized users.

Security identifiers

  • CCE-26371-5

Result for Verify /etc/grub.conf User Ownership

Result: pass

Rule ID: user_owner_grub_conf

Time: 2013-09-27 19:03

Severity: medium

The file /etc/grub.conf should be owned by the root user to prevent destruction or modification of the file. To properly set the owner of /etc/grub.conf, run the command:

# chown root /etc/grub.conf 

Only root should be able to modify important boot parameters.

Security identifiers

  • CCE-26995-1

Result for Verify /etc/grub.conf Group Ownership

Result: pass

Rule ID: group_owner_grub_conf

Time: 2013-09-27 19:03

Severity: medium

The file /etc/grub.conf should be group-owned by the root group to prevent destruction or modification of the file. To properly set the group owner of /etc/grub.conf, run the command:

# chgrp root /etc/grub.conf 

The root group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.

Security identifiers

  • CCE-27022-3

Result for Verify /boot/grub/grub.conf Permissions

Result: pass

Rule ID: permissions_grub_conf

Time: 2013-09-27 19:03

Severity: medium

File permissions for /boot/grub/grub.conf should be set to 600, which is the default. To properly set the permissions of /boot/grub/grub.conf, run the command:

# chmod 600 /boot/grub/grub.conf

Proper permissions ensure that only the root user can modify important boot parameters.

Security identifiers

  • CCE-26949-8

Result for Set Boot Loader Password

Result: fail

Rule ID: bootloader_password

Time: 2013-09-27 19:03

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 Require Authentication for Single User Mode

Result: fail

Rule ID: require_singleuser_auth

Time: 2013-09-27 19:03

Severity: medium

Single-user mode is intended as a system recovery method, providing a single user root access to the system by providing a boot option at startup. By default, no authentication is performed if single-user mode is selected.

To require entry of the root password even if the system is started in single-user mode, add or correct the following line in the file /etc/sysconfig/init:

SINGLE=/sbin/sulogin

This prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password.

Security identifiers

  • CCE-27040-5

Result for Disable Ctrl-Alt-Del Reboot Activation

Result: notchecked

Rule ID: disable_ctrlaltdel_reboot

Time: 2013-09-27 19:03

Severity: high

By default, the system includes the following line in /etc/init/control-alt-delete.conf to reboot the system when the Ctrl-Alt-Del key sequence is pressed:

exec /sbin/shutdown -r now "Control-Alt-Delete pressed"

To configure the system to log a message instead of rebooting the system, alter that line to read as follows:
exec /usr/bin/logger -p security.info "Control-Alt-Delete pressed"

A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In the GNOME graphical environment, risk of unintentional reboot from the Ctrl-Alt-Del sequence is reduced because the user will be prompted before any action is taken.

Result for Disable Interactive Boot

Result: fail

Rule ID: disable_interactive_boot

Time: 2013-09-27 19:03

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

Result for Set GNOME Login Inactivity Timeout

Result: fail

Rule ID: set_screensaver_inactivity_timeout

Time: 2013-09-27 19:03

Severity: medium

Run the following command to set the idle time-out value for inactivity in the GNOME desktop to 15 minutes:

# gconftool-2 \
  --direct \
  --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
  --type int \
  --set /apps/gnome-screensaver/idle_delay 15

Setting the idle delay controls when the screensaver will start, and can be combined with screen locking to prevent access from passersby.

Security identifiers

  • CCE-26828-4

Result for GNOME Desktop Screensaver Mandatory Use

Result: fail

Rule ID: enable_screensaver_after_idle

Time: 2013-09-27 19:03

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: fail

Rule ID: enable_screensaver_password_lock

Time: 2013-09-27 19:03

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: fail

Rule ID: set_blank_screensaver

Time: 2013-09-27 19:03

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 Install the screen Package

Result: pass

Rule ID: package_screen_installed

Time: 2013-09-27 19:03

Severity: low

To enable console screen locking, install the screen package:

# yum install screen
Instruct users to begin new terminal sessions with the following command:
$ screen
The console can now be locked with the following key combination:
ctrl+a x

Installing screen ensures a console locking capability is available for users who may need to suspend console logins.

Security identifiers

  • CCE-26940-7

Remediation script

                yum -y install screen

              

Result for Enable Smart Card Login

Result: notchecked

Rule ID: smartcard_auth

Time: 2013-09-27 19:03

Severity: medium

To enable smart card authentication, consult the documentation at:

  • https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Managing_Smart_Cards/enabling-smart-card-login.html

Smart card login provides two-factor authentication stronger than that provided by a username/password combination. Smart cards leverage a PKI (public key infrastructure) in order to provide and verify credentials.

Result for Modify the System Login Banner

Result: fail

Rule ID: set_system_login_banner

Time: 2013-09-27 19:03

Severity: medium

To configure the system login banner:

Edit /etc/issue. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.


OR:

I've read & consent to terms in IS user agreem't.

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

Security identifiers

  • CCE-26974-6

Remediation script

                login_banner_text="You[\s\n]+are[\s\n]+accessing[\s\n]+a[\s\n]+U.S.[\s\n]+Government[\s\n]+\(USG\)[\s\n]+Information[\s\n]+System[\s\n]+\(IS\)[\s\n]+that[\s\n]+is[\s\n]+provided[\s\n]+for[\s\n]+USG-authorized[\s\n]+use[\s\n]+only.[\s\n]*By[\s\n]+using[\s\n]+this[\s\n]+IS[\s\n]+\(which[\s\n]+includes[\s\n]+any[\s\n]+device[\s\n]+attached[\s\n]+to[\s\n]+this[\s\n]+IS\),[\s\n]+you[\s\n]+consent[\s\n]+to[\s\n]+the[\s\n]+following[\s\n]+conditions\:[\s\n]*-[\s\n]*The[\s\n]+USG[\s\n]+routinely[\s\n]+intercepts[\s\n]+and[\s\n]+monitors[\s\n]+communications[\s\n]+on[\s\n]+this[\s\n]+IS[\s\n]+for[\s\n]+purposes[\s\n]+including,[\s\n]+but[\s\n]+not[\s\n]+limited[\s\n]+to,[\s\n]+penetration[\s\n]+testing,[\s\n]+COMSEC[\s\n]+monitoring,[\s\n]+network[\s\n]+operations[\s\n]+and[\s\n]+defense,[\s\n]+personnel[\s\n]+misconduct[\s\n]+\(PM\),[\s\n]+law[\s\n]+enforcement[\s\n]+\(LE\),[\s\n]+and[\s\n]+counterintelligence[\s\n]+\(CI\)[\s\n]+investigations.[\s\n]*-[\s\n]*At[\s\n]+any[\s\n]+time,[\s\n]+the[\s\n]+USG[\s\n]+may[\s\n]+inspect[\s\n]+and[\s\n]+seize[\s\n]+data[\s\n]+stored[\s\n]+on[\s\n]+this[\s\n]+IS.[\s\n]*-[\s\n]*Communications[\s\n]+using,[\s\n]+or[\s\n]+data[\s\n]+stored[\s\n]+on,[\s\n]+this[\s\n]+IS[\s\n]+are[\s\n]+not[\s\n]+private,[\s\n]+are[\s\n]+subject[\s\n]+to[\s\n]+routine[\s\n]+monitoring,[\s\n]+interception,[\s\n]+and[\s\n]+search,[\s\n]+and[\s\n]+may[\s\n]+be[\s\n]+disclosed[\s\n]+or[\s\n]+used[\s\n]+for[\s\n]+any[\s\n]+USG-authorized[\s\n]+purpose.[\s\n]*-[\s\n]*This[\s\n]+IS[\s\n]+includes[\s\n]+security[\s\n]+measures[\s\n]+\(e.g.,[\s\n]+authentication[\s\n]+and[\s\n]+access[\s\n]+controls\)[\s\n]+to[\s\n]+protect[\s\n]+USG[\s\n]+interests[\s\n]+--[\s\n]+not[\s\n]+for[\s\n]+your[\s\n]+personal[\s\n]+benefit[\s\n]+or[\s\n]+privacy.[\s\n]*-[\s\n]*Notwithstanding[\s\n]+the[\s\n]+above,[\s\n]+using[\s\n]+this[\s\n]+IS[\s\n]+does[\s\n]+not[\s\n]+constitute[\s\n]+consent[\s\n]+to[\s\n]+PM,[\s\n]+LE[\s\n]+or[\s\n]+CI[\s\n]+investigative[\s\n]+searching[\s\n]+or[\s\n]+monitoring[\s\n]+of[\s\n]+the[\s\n]+content[\s\n]+of[\s\n]+privileged[\s\n]+communications,[\s\n]+or[\s\n]+work[\s\n]+product,[\s\n]+related[\s\n]+to[\s\n]+personal[\s\n]+representation[\s\n]+or[\s\n]+services[\s\n]+by[\s\n]+attorneys,[\s\n]+psychotherapists,[\s\n]+or[\s\n]+clergy,[\s\n]+and[\s\n]+their[\s\n]+assistants.[\s\n]+Such[\s\n]+communications[\s\n]+and[\s\n]+work[\s\n]+product[\s\n]+are[\s\n]+private[\s\n]+and[\s\n]+confidential.[\s\n]+See[\s\n]+User[\s\n]+Agreement[\s\n]+for[\s\n]+details."
cat <<EOF >/etc/issue
$login_banner_text
EOF

              

Result for Enable GUI Warning Banner

Result: fail

Rule ID: enable_gdm_login_banner

Time: 2013-09-27 19:03

Severity: medium

To enable displaying a login warning banner in the GNOME Display Manager's login screen, run the following command:

sudo -u gdm gconftool-2 \
  --type bool \
  --set /apps/gdm/simple-greeter/banner_message_enable true
To display a banner, this setting must be enabled and then banner text must also be set.

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

Security identifiers

  • CCE-27195-7

Result for Set GUI Warning Banner Text

Result: notchecked

Rule ID: set_gdm_login_banner_text

Time: 2013-09-27 19:03

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 Kernel Parameter for Sending ICMP Redirects by Default

Result: fail

Rule ID: disable_sysctl_ipv4_default_send_redirects

Time: 2013-09-27 19:03

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

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

Result: fail

Rule ID: disable_sysctl_ipv4_all_send_redirects

Time: 2013-09-27 19:03

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: disable_sysctl_ipv4_ip_forward

Time: 2013-09-27 19:03

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: set_sysctl_net_ipv4_conf_all_accept_source_route

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_all_accept_redirects

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_all_secure_redirects

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_all_log_martians

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_default_accept_source_route

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_default_accept_redirects

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_default_secure_redirects

Time: 2013-09-27 19:03

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: set_sysctl_net_ipv4_icmp_echo_ignore_broadcasts

Time: 2013-09-27 19:03

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: set_sysctl_net_ipv4_icmp_ignore_bogus_error_responses

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_tcp_syncookies

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_all_rp_filter

Time: 2013-09-27 19:03

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: fail

Rule ID: set_sysctl_net_ipv4_conf_default_rp_filter

Time: 2013-09-27 19:03

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 Bluetooth Service

Result: pass

Rule ID: service_bluetooth_disabled

Time: 2013-09-27 19:03

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

Result for Disable Bluetooth Kernel Modules

Result: fail

Rule ID: kernel_module_bluetooth_disabled

Time: 2013-09-27 19:03

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: fail

Rule ID: disable_ipv6_module_loading

Time: 2013-09-27 19:03

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 Accepting IPv6 Redirects

Result: fail

Rule ID: set_sysctl_ipv6_default_accept_redirects

Time: 2013-09-27 19:03

Severity: medium

To set the runtime status of the net.ipv6.conf.default.accept_redirects kernel parameter, run the following command:

# sysctl -w net.ipv6.conf.default.accept_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf:
net.ipv6.conf.default.accept_redirects = 0

An illicit ICMP redirect message could result in a man-in-the-middle attack.

Security identifiers

  • CCE-27166-8

Result for Verify ip6tables Enabled if Using IPv6

Result: pass

Rule ID: enable_ip6tables

Time: 2013-09-27 19:03

Severity: medium

The ip6tables service can be enabled with the following command:

# chkconfig --level 2345 ip6tables on

The ip6tables service provides the system's host-based firewalling capability for IPv6 and ICMPv6.

Security identifiers

  • CCE-27006-6

Result for Verify iptables Enabled

Result: pass

Rule ID: enable_iptables

Time: 2013-09-27 19:03

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

Result for Set Default iptables Policy for Incoming Packets

Result: fail

Rule ID: set_iptables_default_rule

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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: fail

Rule ID: disable_protocol_dccp

Time: 2013-09-27 19:03

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

Result for Disable SCTP Support

Result: fail

Rule ID: disable_protocol_sctp

Time: 2013-09-27 19:03

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

Result for Disable RDS Support

Result: fail

Rule ID: disable_protocol_rds

Time: 2013-09-27 19:03

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

Result for Disable TIPC Support

Result: fail

Rule ID: disable_protocol_tipc

Time: 2013-09-27 19:03

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

Result for Install openswan Package

Result: pass

Rule ID: install_openswan

Time: 2013-09-27 19:03

Severity: low

The Openswan package provides an implementation of IPsec and IKE, which permits the creation of secure tunnels over untrusted networks. The openswan package can be installed with the following command:

# yum install openswan

Providing the ability for remote users or systems to initiate a secure VPN connection protects information when it is transmitted over a wide area network.

Security identifiers

  • CCE-27626-1

Result for Ensure rsyslog is Installed

Result: pass

Rule ID: package_rsyslog_installed

Time: 2013-09-27 19:03

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

Result for Enable rsyslog Service

Result: pass

Rule ID: service_rsyslog_enabled

Time: 2013-09-27 19:03

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

Result for Ensure Log Files Are Owned By Appropriate User

Result: pass

Rule ID: userowner_rsyslog_files

Time: 2013-09-27 19:03

Severity: medium

The 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 owner:

$ ls -l LOGFILE
If the owner is not root, run the following command to correct this:
# chown 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-26812-8

Result for Ensure Log Files Are Owned By Appropriate Group

Result: unknown

Rule ID: groupowner_rsyslog_files

Time: 2013-09-27 19:03

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 System Log Files Have Correct Permissions

Result: unknown

Rule ID: rsyslog_file_permissions

Time: 2013-09-27 19:03

Severity: medium

The file permissions for all log files written by rsyslog should be set to 600, or more restrictive. 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 permissions:

$ ls -l LOGFILE
If the permissions are not 600 or more restrictive, run the following command to correct this:
# chmod 0600 LOGFILE

Log files can contain valuable information regarding system configuration. If the system log files are not protected unauthorized users could change the logged data, eliminating their forensic value.

Security identifiers

  • CCE-27190-8

Result for Ensure Logs Sent To Remote Host

Result: fail

Rule ID: rsyslog_send_messages_to_logserver

Time: 2013-09-27 19:03

Severity: low

To configure rsyslog to send logs to a remote log server, open /etc/rsyslog.conf and read and understand the last section of the file, which describes the multiple directives necessary to activate remote logging. Along with these other directives, the system can be configured to forward its logs to a particular log server by adding or correcting one of the following lines, substituting loghost.example.com appropriately. The choice of protocol depends on the environment of the system; although TCP and RELP provide more reliable message delivery, they may not be supported in all environments.
To use UDP for log message delivery:

*.* @loghost.example.com

To use TCP for log message delivery:
*.* @@loghost.example.com

To use RELP for log message delivery:
*.* :omrelp:loghost.example.com

A log server (loghost) receives syslog messages from one or more systems. This data can be used as an additional log source in the event a system is compromised and its local logs are suspect. Forwarding log messages to a remote loghost also provides system administrators with a centralized place to view the status of multiple hosts within the enterprise.

Security identifiers

  • CCE-26801-1

Result for Ensure Logrotate Runs Periodically

Result: unknown

Rule ID: ensure_logrotate_activated

Time: 2013-09-27 19:03

Severity: low

The logrotate service should be enabled.

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: enable_auditd_service

Time: 2013-09-27 19:03

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

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

Result: fail

Rule ID: enable_auditd_bootloader

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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.

Result for Configure auditd Max Log File Size

Result: pass

Rule ID: configure_auditd_max_log_file

Time: 2013-09-27 19:03

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.

Result for Configure auditd max_log_file_action Upon Reaching Maximum Log Size

Result: pass

Rule ID: configure_auditd_max_log_file_action

Time: 2013-09-27 19:03

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: fail

Rule ID: configure_auditd_space_left_action

Time: 2013-09-27 19:03

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: fail

Rule ID: configure_auditd_admin_space_left_action

Time: 2013-09-27 19:03

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

  • ignore

  • syslog

  • email

  • exec

  • suspend

  • single

  • halt

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.

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

Result for Configure auditd mail_acct Action on Low Disk Space

Result: pass

Rule ID: configure_auditd_action_mail_acct

Time: 2013-09-27 19:03

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 Record attempts to alter time through adjtimex

Result: fail

Rule ID: audit_rules_time_adjtimex

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_time_settimeofday

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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 time" 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: fail

Rule ID: audit_rules_time_clock_settime

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_time_watch_localtime

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_account_changes

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_network_modifications

Time: 2013-09-27 19:03

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 exit,always -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: audit_logs_permissions

Time: 2013-09-27 19:03

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 Record Events that Modify the System's Mandatory Access Controls

Result: fail

Rule ID: audit_mac_changes

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_chmod

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_chown

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_fchmod

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_fchmodat

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_fchown

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_fchownat

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_fremovexattr

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_fsetxattr

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_lchown

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_lremovexattr

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_lsetxattr

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_removexattr

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_rules_dac_modification_setxattr

Time: 2013-09-27 19:03

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 Ensure auditd Collects Unauthorized Access Attempts to Files (unsuccessful)

Result: fail

Rule ID: audit_file_access

Time: 2013-09-27 19:03

Severity: low

At a minimum the audit system should collect unauthorized file accesses 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 creat -S open -S openat -S truncate \
    -S ftruncate -F exit=-EACCES -F auid>=500 -F auid!=4294967295 -k access
-a always,exit -F arch=ARCH -S creat -S open -S openat -S truncate \
    -S ftruncate -F exit=-EPERM -F auid>=500 -F auid!=4294967295 -k access

Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.

Security identifiers

  • CCE-26712-0

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

Result: fail

Rule ID: audit_privileged_commands

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_media_exports

Time: 2013-09-27 19:03

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 File Deletion Events by User

Result: fail

Rule ID: audit_file_deletions

Time: 2013-09-27 19:03

Severity: low

At a minimum the audit system should collect file deletion 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 unlink -S unlinkat -S rename -S renameat \
    -F auid>=500 -F auid!=4294967295 -k delete

Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.

Security identifiers

  • CCE-26651-0

Result for Ensure auditd Collects System Administrator Actions

Result: fail

Rule ID: audit_sysadmin_actions

Time: 2013-09-27 19:03

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: fail

Rule ID: audit_kernel_module_loading

Time: 2013-09-27 19:03

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 Disable xinetd Service

Result: pass

Rule ID: disable_xinetd

Time: 2013-09-27 19:03

Severity: medium

The xinetd service can be disabled with the following command:

# chkconfig xinetd off

The xinetd service provides a dedicated listener service for some programs, which is no longer necessary for commonly-used network services. Disabling it ensures that these uncommon services are not running, and also prevents attacks against xinetd itself.

Security identifiers

  • CCE-27046-2

Result for Uninstall xinetd Package

Result: pass

Rule ID: uninstall_xinetd

Time: 2013-09-27 19:03

Severity: low

The xinetd package can be uninstalled with the following command:

# yum erase xinetd

Removing the xinetd package decreases the risk of the xinetd service's accidental (or intentional) activation.

Security identifiers

  • CCE-27005-8

Remediation script

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

              

Result for Disable telnet Service

Result: fail

Rule ID: disable_telnet_service

Time: 2013-09-27 19:03

Severity: high

The telnet service can be disabled with the following command:

# chkconfig telnet off

The telnet protocol uses unencrypted network communication, 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. The telnet protocol is also subject to man-in-the-middle attacks.

Security identifiers

  • CCE-26836-7

Result for Uninstall telnet-server Package

Result: pass

Rule ID: uninstall_telnet_server

Time: 2013-09-27 19:03

Severity: high

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

# yum erase telnet-server

Removing the telnet-server package decreases the risk of the telnet service's accidental (or intentional) activation.

Security identifiers

  • CCE-27073-6

Remediation script

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

              

Result for Uninstall rsh-server Package

Result: pass

Rule ID: uninstall_rsh-server

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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 Remove Rsh Trust Files

Result: pass

Rule ID: no_rsh_trust_files

Time: 2013-09-27 19:03

Severity: high

The files /etc/hosts.equiv and ~/.rhosts (in each user's home directory) list remote hosts and users that are trusted by the local system when using the rshd daemon. To remove these files, run the following command to delete them from any location:

# rm /etc/hosts.equiv
$ rm ~/.rhosts

Trust files are convenient, but when used in conjunction with the R-services, they can allow unauthenticated access to a system.

Security identifiers

  • CCE-27270-8

Result for Uninstall ypserv Package

Result: pass

Rule ID: uninstall_ypserv

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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

Result for Disable Network Console (netconsole)

Result: pass

Rule ID: service_netconsole_disabled

Time: 2013-09-27 19:03

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

Result for Disable ntpdate Service (ntpdate)

Result: pass

Rule ID: service_ntpdate_disabled

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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 but it 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

Result for Disable Apache Qpid (qpidd)

Result: pass

Rule ID: service_qpidd_disabled

Time: 2013-09-27 19:03

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

Result for Disable Network Router Discovery Daemon (rdisc)

Result: pass

Rule ID: service_rdisc_disabled

Time: 2013-09-27 19:03

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

Result for Disable Red Hat Network Service (rhnsd)

Result: fail

Rule ID: service_rhnsd_disabled

Time: 2013-09-27 19:03

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

Result for Enable cron Service

Result: pass

Rule ID: enable_cron

Time: 2013-09-27 19:03

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

Result for Allow Only SSH Protocol 2

Result: pass

Rule ID: sshd_allow_only_protocol2

Time: 2013-09-27 19:03

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 Set SSH Idle Timeout Interval

Result: fail

Rule ID: sshd_set_idle_timeout

Time: 2013-09-27 19:03

Severity: low

SSH allows administrators to set an idle timeout interval. After this interval has passed, the idle user will be automatically logged out.

To set an idle timeout interval, edit the following line in /etc/ssh/sshd_config as follows:

ClientAliveInterval interval
The timeout interval is given in seconds. To have a timeout of 15 minutes, set interval to 900.

If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made here. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.

Causing idle users to be automatically logged out guards against compromises one system leading trivially to compromises on another.

Security identifiers

  • CCE-26919-1

Result for Set SSH Client Alive Count

Result: fail

Rule ID: sshd_set_keepalive

Time: 2013-09-27 19:03

Severity: low

To ensure the SSH idle timeout occurs precisely when the ClientAliveCountMax is set, edit /etc/ssh/sshd_config as follows:

ClientAliveCountMax 0

This ensures a user login will be terminated as soon as the ClientAliveCountMax is reached.

Security identifiers

  • CCE-26282-4

Result for Disable SSH Support for .rhosts Files

Result: pass

Rule ID: sshd_disable_rhosts

Time: 2013-09-27 19:03

Severity: medium

SSH can emulate the behavior of the obsolete rsh command in allowing users to enable insecure access to their accounts via .rhosts files.

To ensure this behavior is disabled, add or correct the following line in /etc/ssh/sshd_config:

IgnoreRhosts yes

SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.

Security identifiers

  • CCE-27124-7

Result for Disable Host-Based Authentication

Result: pass

Rule ID: disable_host_auth

Time: 2013-09-27 19:03

Severity: medium

SSH's cryptographic host-based authentication is more secure than .rhosts authentication, since hosts are cryptographically authenticated. However, it is not recommended that hosts unilaterally trust one another, even within an organization.

To disable host-based authentication, add or correct the following line in /etc/ssh/sshd_config:

HostbasedAuthentication no

SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.

Security identifiers

  • CCE-27091-8

Result for Disable SSH Root Login

Result: pass

Rule ID: sshd_disable_root_login

Time: 2013-09-27 19:03

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

Result for Disable SSH Access via Empty Passwords

Result: fail

Rule ID: sshd_disable_empty_passwords

Time: 2013-09-27 19:03

Severity: high

To explicitly disallow remote login from accounts with empty passwords, add or correct the following line in /etc/ssh/sshd_config:

PermitEmptyPasswords no
Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.

Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.

Security identifiers

  • CCE-26887-0

Result for Enable SSH Warning Banner

Result: fail

Rule ID: sshd_enable_warning_banner

Time: 2013-09-27 19:03

Severity: medium

To enable the warning banner and ensure it is consistent across the system, add or correct the following line in /etc/ssh/sshd_config:

Banner /etc/issue
Another section contains information on how to create an appropriate system-wide warning banner.

The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.

Security identifiers

  • CCE-27112-2

Result for Do Not Allow SSH Environment Options

Result: fail

Rule ID: sshd_do_not_permit_user_env

Time: 2013-09-27 19:03

Severity: low

To ensure users are not able to present environment options to the SSH daemon, add or correct the following line in /etc/ssh/sshd_config:

PermitUserEnvironment no

SSH environment options potentially allow users to bypass access restriction in some configurations.

Security identifiers

  • CCE-27201-3

Result for Use Only Approved Ciphers

Result: fail

Rule ID: sshd_use_approved_ciphers

Time: 2013-09-27 19:03

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

Result for Disable X Windows Startup By Setting Runlevel

Result: pass

Rule ID: disable_xwindows_with_runlevel

Time: 2013-09-27 19:03

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 Remove the X Windows Package Group

Result: pass

Rule ID: packagegroup_xwindows_remove

Time: 2013-09-27 19:03

Severity: low

Removing all packages which constitute the X Window System ensures users or malicious software cannot start X. To do so, run the following command:

# yum groupremove "X Window System"

Unnecessary packages should not be installed to decrease the attack surface of the system.

Security identifiers

  • CCE-27198-1

Result for Disable Avahi Server Software

Result: pass

Rule ID: disable_avahi

Time: 2013-09-27 19:03

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 DHCP Client

Result: pass

Rule ID: disable_dhcp_client

Time: 2013-09-27 19:03

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=static

  • 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: enable_ntpd

Time: 2013-09-27 19:03

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

Result for Specify a Remote NTP Server

Result: pass

Rule ID: ntpd_specify_remote_server

Time: 2013-09-27 19:03

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. Using a trusted NTP server provided by your organization is recommended.

Security identifiers

  • CCE-27098-3

Result for Enable Postfix Service

Result: pass

Rule ID: service_postfix_enable

Time: 2013-09-27 19:03

Severity: low

The Postfix mail transfer agent is used for local mail delivery within the system. The default configuration only listens for connections to the default SMTP port (port 25) on the loopback interface (127.0.0.1). It is recommended to leave this service enabled for local mail delivery. The postfix service can be enabled with the following command:

# chkconfig --level 2345 postfix on

Local mail delivery is essential to some system maintenance and notification tasks.

Security identifiers

  • CCE-26325-1

Result for Uninstall Sendmail Package

Result: pass

Rule ID: package_sendmail_removed

Time: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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: 2013-09-27 19:03

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 Mount Remote Filesystems with nodev

Result: pass

Rule ID: use_nodev_option_on_nfs_mounts

Time: 2013-09-27 19:03

Severity: medium

Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of any NFS mounts.

Legitimate device files should only exist in the /dev directory. NFS mounts should not present device files to users.

Security identifiers

  • CCE-27090-0

Result for Mount Remote Filesystems with nosuid

Result: pass

Rule ID: use_nosuid_option_on_nfs_mounts

Time: 2013-09-27 19:03

Severity: medium

Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of any NFS mounts.

NFS mounts should not present suid binaries to users. Only vendor-supplied suid executables should be installed to their default location on the local filesystem.

Security identifiers

  • CCE-26972-0

Result for Ensure Insecure File Locking is Not Allowed

Result: notchecked

Rule ID: no_insecure_locks_exports

Time: 2013-09-27 19:03

Severity: medium

By default the NFS server requires secure file-lock requests, which require credentials from the client in order to lock a file. Most NFS clients send credentials with file lock requests, however, there are a few clients that do not send credentials when requesting a file-lock, allowing the client to only be able to lock world-readable files. To get around this, the insecure_locks option can be used so these clients can access the desired export. This poses a security risk by potentially allowing the client access to data for which it does not have authorization. Remove any instances of the insecure_locks option from the file /etc/exports.

Allowing insecure file locking could allow for sensitive data to be viewed or edited by an unauthorized user.

Security identifiers

  • CCE-27167-6

Result for Enable Logging of All FTP Transactions

Result: notchecked

Rule ID: ftp_log_transactions

Time: 2013-09-27 19:03

Severity: low

Add or correct the following configuration options within the vsftpd configuration file, located at /etc/vsftpd/vsftpd.conf:

xferlog_enable=YES
xferlog_std_format=NO
log_ftp_protocol=YES

If verbose logging to vsftpd.log is done, sparse logging of downloads to /var/log/xferlog will not also occur. However, the information about what files were downloaded is included in the information logged to vsftpd.log

To trace malicious activity facilitated by the FTP service, it must be configured to ensure that all commands sent to the FTP server are logged using the verbose vsftpd log format. The default vsftpd log file is /var/log/vsftpd.log.

Security identifiers

  • CCE-27142-9

Result for Create Warning Banners for All FTP Users

Result: notchecked

Rule ID: ftp_present_banner

Time: 2013-09-27 19:03

Severity: medium

Edit the vsftpd configuration file, which resides at /etc/vsftpd/vsftpd.conf by default. Add or correct the following configuration options:

banner_file=/etc/issue

This setting will cause the system greeting banner to be used for FTP connections as well.

Security identifiers

  • CCE-27145-2

Result for Require Client SMB Packet Signing, if using smbclient

Result: pass

Rule ID: require_smb_client_signing

Time: 2013-09-27 19:03

Severity: low

To require samba clients running smbclient to use packet signing, add the following to the [global] section of the Samba configuration file, /etc/samba/smb.conf:

client signing = mandatory
Requiring samba clients such as smbclient to use packet signing ensures they can only communicate with servers that support packet signing.

Packet signing can prevent man-in-the-middle attacks which modify SMB packets in transit.

Security identifiers

  • CCE-26328-5

Result for Require Client SMB Packet Signing, if using mount.cifs

Result: pass

Rule ID: require_smb_client_signing_mount.cifs

Time: 2013-09-27 19:03

Severity: low

Require packet signing of clients who mount Samba shares using the mount.cifs program (e.g., those who specify shares in /etc/fstab). To do so, ensure signing options (either sec=krb5i or sec=ntlmv2i) are used.

See the mount.cifs(8) man page for more information. A Samba client should only communicate with servers who can support SMB packet signing.

Packet signing can prevent man-in-the-middle attacks which modify SMB packets in transit.

Security identifiers

  • CCE-26792-2

Result for Configure SNMP Service to Use Only SNMPv3 or Newer

Result: notchecked

Rule ID: snmpd_use_newer_protocol

Time: 2013-09-27 19:03

Severity: medium

Edit /etc/snmp/snmpd.conf, removing any references to v1, v2c, or com2sec. Upon doing that, restart the SNMP service:

# service snmpd restart

Earlier versions of SNMP are considered insecure, as they potentially allow unauthorized access to detailed system management information.

Result for Ensure Default Password Is Not Used

Result: notchecked

Rule ID: snmpd_not_default_password

Time: 2013-09-27 19:03

Severity: medium

Edit /etc/snmp/snmpd.conf, remove default community string public. Upon doing that, restart the SNMP service:

# service snmpd restart

Presence of the default SNMP password enables querying of different system aspects and could result in unauthorized knowledge of the system.