when is dual ARCH required in audit.rules?

Trevor Vaughan tvaughan at onyxpoint.com
Mon Nov 2 18:07:52 UTC 2015


Hi Steve,

Do you know if there is a way to detect if you're running on a system that
has not been compiled with 32-bit support?

SIMP is automatically generating the 32/64 split based on whether or not
you're on a 32 or 64-bit platform but I haven't encountered the situation
that you mentioned in the wild and would like to be able to handle it
properly.

Reference: https://github.com/simp/pupmod-simp-auditd

Thanks,

Trevor

On Tue, Oct 27, 2015 at 11:29 AM, Steve Grubb <sgrubb at redhat.com> wrote:

> On Tuesday, October 27, 2015 10:00:07 AM Robert Jacobson wrote:
> > I've recently been trying to reconcile the audit.rules on my systems vs.
> > the scap-security-guide, and I'm confused about the ARCH rules.
>
> Right. I sent feedback internally to the project to tell them that what is
> written is not efficient and not clear. That section is being re-written.
>
> > When is it required to check both 32- and 64-bit architectures?
>
> Whenever you have a system that is bi-arch. That would commonly be 64 bit
> systems. But it is possible to compile 64 bit kernels that have no 32 bit
> ABI.
>
>
> > e.g. the guide says both 32- and 64-bit rules are required to check for
> > unauthorized access attempts:
>
> That is a fact. The stig.rules shipped in the audit package is an accurate
> starting point for 64 bit systems needing stig compliance.
>
>
> > # Unauthorized Access attempts
> (audit_rules_unsuccessful_file_modification)
> > -a always,exit -F arch=b32 -S creat -S open -S openat -S
> > open_by_handle_at -S truncate -S ftruncate -F exit=-EACCES -F auid>=500
> > -F auid!=4294967295 -k access
> > -a always,exit -F arch=b32 -S creat -S open -S openat -S
> > open_by_handle_at -S truncate -S ftruncate -F exit=-EPERM -F auid>=500
> > -F auid!=4294967295 -k access
> > -a always,exit -F arch=b64 -S creat -S open -S openat -S
> > open_by_handle_at -S truncate -S ftruncate -F exit=-EACCES -F auid>=500
> > -F auid!=4294967295 -k access
> > -a always,exit -F arch=b64 -S creat -S open -S openat -S
> > open_by_handle_at -S truncate -S ftruncate -F exit=-EPERM -F auid>=500
> > -F auid!=4294967295 -k access
>
> This looks correct assuming that real users start at 500. That number needs
> adjusting up if you start users at a higher number.
>
> > But for modifying the network environment, only the 64-bit rule is
> required:
> >
> > # Network changes ( audit_rules_networkconfig_modification )
> > -a always,exit -F arch=b64 -S sethostname -S setdomainname -k
> > audit_rules_networkconfig_modification
>
> A 32 bit rule is also needed.
>
> > I don't understand why the 32-bit check is required for open() calls but
> > not sethostname() calls?
>
> Its a mistake. I am working with them to correct the SSG and it has
> problems
> beyond auditing. But its being patched quickly and should be ready to use
> soon.
>
> -Steve
> --
> SCAP Security Guide mailing list
> scap-security-guide at lists.fedorahosted.org
> https://lists.fedorahosted.org/mailman/listinfo/scap-security-guide
> https://github.com/OpenSCAP/scap-security-guide/
>



-- 
Trevor Vaughan
Vice President, Onyx Point, Inc
(410) 541-6699

-- This account not approved for unencrypted proprietary information --
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.fedorahosted.org/pipermail/scap-security-guide/attachments/20151102/65c2254d/attachment-0001.html>


More information about the scap-security-guide mailing list