[PATCH] [RHEL/6] When checking GRUB bootloader security ("password" directive being present in grub.conf configuration file) succeed only in case there's uncommented occurrence present
Jan Lieskovsky
jlieskov at redhat.com
Wed Mar 5 17:51:17 UTC 2014
----- Original Message -----
> From: "Shawn Wells" <shawn at redhat.com>
> To: scap-security-guide at lists.fedorahosted.org
> Sent: Wednesday, March 5, 2014 6:16:55 PM
> Subject: Re: [PATCH] [RHEL/6] When checking GRUB bootloader security ("password" directive being present in grub.conf
> configuration file) succeed only in case there's uncommented occurrence present
>
> On 3/5/14, 12:13 PM, Jan Lieskovsky wrote:
>
>
>
> Hello folks,
>
> another reasonable change originally pointed out by Tomas Heinrich
> for USGCB content, but applicable also against SSG content.
>
> The current bootloader_password.xml OVAL check implementation checks
> for presence of:
>
> password --encrypted .*
>
> string in /etc/grub.conf configuration file. But without having the heading /
> starting anchor defined (IOW explicitly allowing only whitespace characters
> from the beginning of the pattern match string). Therefore it would return
> success for all three of the following cases (which is wrong):
>
> password --encrypted .*
> #password --encrypted .*
> #\tpassword --encrypted .*
>
> Therefore add starting / heading anchor requirement (in the form of ^[\s]*)
> which ensures:
>
> password --encrypted .* will still pass, but
> #password --encrypted .* and
> #\tpassword --encrypted .* will both fail.
>
> Proposed change briefly tested and seems to be working properly.
>
> Please review.
>
> Thank you && Regards, Jan.
> --
> Jan iankko Lieskovsky / Red Hat Security Technologies Team
>
> 0001-RHEL-6-When-checking-GRUB-bootloader-security-passwo.patch
> From 0a29eb7e7be27191ead7110ee5674ca7156c9f03 Mon Sep 17 00:00:00 2001
> From: Jan Lieskovsky <jlieskov at redhat.com> Date: Wed, 5 Mar 2014 17:53:35
> +0100
> Subject: [PATCH] [RHEL/6] When checking GRUB bootloader security ("password"
> directive being present in grub.conf configuration file) succeed only in
> case
> there's uncommented occurrence present (IOW add heading anchor ensuring
> occurrences "in-the-middle-of-string" wouldn't meet the requirement)
>
> Signed-off-by: Jan Lieskovsky <jlieskov at redhat.com> ---
> RHEL/6/input/checks/bootloader_password.xml | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/RHEL/6/input/checks/bootloader_password.xml
> b/RHEL/6/input/checks/bootloader_password.xml
> index 6545c4d..201c369 100644
> --- a/RHEL/6/input/checks/bootloader_password.xml
> +++ b/RHEL/6/input/checks/bootloader_password.xml
> @@ -18,7 +18,7 @@
> <ind:textfilecontent54_object id="object_bootloader_password" version="1">
> <ind:path>/etc</ind:path>
> <ind:filename>grub.conf</ind:filename>
> - <ind:pattern operation="pattern
> match">password[\s]+--encrypted[\s]+.*</ind:pattern>
> + <ind:pattern operation="pattern
> match">^[\s]*password[\s]+--encrypted[\s]+.*</ind:pattern>
> <ind:instance datatype="int">1</ind:instance>
> </ind:textfilecontent54_object>
> </def-group>
> --
> 1.8.3.1
> Completely sane. I'm sure there are other regex's like this within the OVAL
> code...
>
> ack.
Thanks, Shawn. Based on:
scap-security-guide]$ grep -A3 -B3 -rHn conf * | grep pattern | grep checks > /tmp/out
search looks you are truly right (at first look there seems to be 30 another cases like this -
details in attached file [some have starting ^, but don't count with possible pre-spaces.
Needs check if the underlying config file format allows them]).
Unless someone beats me to it, will go through them case-by-case tomorrow and propose fixes
where appropriate / applicable (but at least the cups based ones seems to be proper candidates.
Further testing will tell more though).
Thank you && Regards, Jan.
--
Jan iankko Lieskovsky / Red Hat Security Technologies Team
>
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