----- Original Message -----
From: "Steve Grubb" <sgrubb(a)redhat.com>
To: "Jan Lieskovsky" <jlieskov(a)redhat.com>
Cc: "SCAP Security Guide" <scap-security-guide(a)lists.fedorahosted.org>
Sent: Tuesday, December 16, 2014 5:20:23 PM
Subject: Re: Configuration testing vs Forensic testing
TL;DR - OVAL is limited in its capabilities. The prose must match what OVAL
On Tuesday, December 16, 2014 10:18:32 AM Jan Lieskovsky wrote:
> First let me summary that:
> * it's great we agreed on the need to separate configuration vs
> runtime checks,
> * we identified the areas which needs fixing.
> But obvious question being what level of separation is required:
> * 1) IOW should each existing rule be turned into a new group, consisting
> of two rules - one for configuration testing, one for runtime testing.
> Then the description of the group would be more generalized form of
> the check, where each of the two new rules would be described according
> to the way they perform the check - IOW the configuration one would
> mention checking configuration files, while the runtime one would focus on
> system actions checking runtime state,
Security guides are always about how to set the system up so that it boots
into the correct configuration. Checking for deviations in enforcement is
sometimes covered, but usually not. There is a little used category of APT
that is Tier III and mostly Windows content. This is the category where that
kind of content belongs. IOW, its not STIG or USGCB or PCI.
Content like a STIG or USGCB is supposed to be a baseline which is all about
how the system boots up. Its content should be pretty slow moving. The APT
category on the other hand is for faster moving guidance on new threats.
> * 2) or is it sufficient to mention in the (HTML version of the guide) that
> the current implementation checks just configuration status (AND the
> runtime state where appropriate) and basically do no changes in current
> XCCDF / OVAL rules implementation,
> * 3) another options / possibility (as
> pointed out by Simon Lukasik - thanks for it!) is the following - modify
> the current rules implementation in the way to keep the configuration tests
> the default ones (IOW when they don't pass the check would fail) and
> simultaneously make the runtime checks the optional ones. The content user
> would be able via e.g. an OVAL variable to instruct the scanner what kind
> of testing should be performed.
> "Check system property" rule
> if ($runtime_check) not set
> check just configuration settings
> check configuration settings
> check runtime settings
> And analogous approach (same global OVAL variable) customizable by the
> SCAP content user would be used for all rules.
We should not be mixing the two use cases. STIG and USGCB should be the on-
> * 4) another option (but maybe just enhancement of case 1)) is to follow
> way to have two dedicated profiles for each of the existing ones (e.g.
> USGCB-configuration and USGCB-runtime) each of them containing rules from
> particular category.
This would be better. But the Forensic case is not an immediate goal or need.
Its more in the nice to have category. In my view, the content right now
should only be the on-disk configuration. The prose should reflect how to
manually in the same way as the SCAP scanner will. Meaning, if the OVAL check
is a filecontent_test, then the prose should use cat + grep or awk.
The fact is that you cannot check the in memory configuration via OVAL for
several things. You can by going to XCCDF and using scripting instead of
But this is already a stretch. The intention is to use regular OVAL
and then make the prose reflect the same test that the scanners will perform.
> * 5) another option is to use "runtime / configuration" (or both of them)
> suffix in the rule title - so for example:
> -- existing "Install Aide" rule would become "Install Aide
> meaning here just runtime check would be performed, while e.g.
> -- existing "Disable the Automounter" would become "Disable the
> Automounter (configuration, runtime)"
> meaning in this case both configuration & runtime checks were
> In my opinion we first need to agree on the way how the separation should
> performed in order to:
> * this separation to be sufficiently clear enough for the content consumers
> * we don't need to change the approach during its implementation (during
> updating actual state to reflect the expectations)
> Should I vote for some of the aforementioned approaches to select one I
> prefer the global OVAL variable approach. E.g. the following:
> * Update existing XCCDF rules description to mention / describe only
> configuration checks,
The prose must match exactly how OVAL tests it.Otherwise you will get
> * Update OVAL checks to perform just configuration testing by default,
This is what they should be doing. Many of the issues I mentioned in the
original email was because the prose did not match the OVAL checks. OVAL has
limited capabilities. It cannot run auditctl or mount or any other external
command. So, the prose need to reflect this limitation and be accurate so
people without a scanner can test by hand and get accurate results. That is
the main issue I was reporting.
Thank you for the clarification, Steve. It's clear now.
Jan iankko Lieskovsky / Red Hat Security Technologies Team