Add modified audit suid privilege function rule for CIS

[Mackemania]

Description:

Add a new rule to accommodate the differences between STIG and CIS regarding execve audit in RHEL8 and RHEL9.

When analyzing a RHEL8 or RHEL9 server with the CIS Workbench after remidiation it fails the settings of audit execve because of a difference between STIG and CIS in recommended settings.

Review Hints:

The new rule is a modified copy of the rule audit_rules_suid_privilege_function.

[openshift-ci]

Hi @Mackemania. Thanks for your PR.

I'm waiting for a ComplianceAsCode member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[github-actions]

Start a new ephemeral environment with changes proposed in this pull request:

rhel8 (from CTF) Environment (using Fedora as testing environment)

Fedora Testing Environment

Oracle Linux 8 Environment

[github-actions]

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New content has different text for rule 'xccdf_org.ssgproject.content_rule_audit_rules_suid_privilege_function'.
--- xccdf_org.ssgproject.content_rule_audit_rules_suid_privilege_function
+++ xccdf_org.ssgproject.content_rule_audit_rules_suid_privilege_function
@@ -91,9 +91,6 @@
 RHEL-08-030000
 
 [reference]:
-4.1.3.2
-
-[reference]:
 SV-230386r854037_rule
 
 [rationale]:

[marcusburghardt]

Could you provide more details about the differences between STIG and CIS regarding the audit_rules_suid_privilege_function rule, please?

[Mackemania]

Could you provide more details about the differences between STIG and CIS regarding the audit_rules_suid_privilege_function rule, please?

STIG definition:

-a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid
-a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgid

CIS definition

-a always,exit -F arch=b32 -C euid!=uid -F auid!=unset -S execve -k user_emulation
-a always,exit -F arch=b64 -C euid!=uid -F auid!=unset -S execve -k user_emulation

STIG has focused on both uid and gid while CIS only cares about the uid. The reason why the CIS Workbench fails the analysis is the missing auid parameter and the euid=0.

[openshift-ci]

@Mackemania: The label(s) /label CIS , /label Ansible , /label Bash cannot be applied. These labels are supported: platform/aws, platform/azure, platform/baremetal, platform/google, platform/libvirt, platform/openstack, ga, tide/merge-method-merge, tide/merge-method-rebase, tide/merge-method-squash, px-approved, docs-approved, qe-approved, downstream-change-needed, rebase/manual, approved, backport-risk-assessed, bugzilla/valid-bug, cherry-pick-approved, jira/valid-bug, staff-eng-approved. Is this label configured under labels -> additional_labels or labels -> restricted_labels in plugin.yaml?

In response to this:

/label CIS
/label Ansible
/label Bash

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[Mackemania]

Would it be possible to rerun the checks? Automatus Fedora / Run Tests (pull_request) got a http 503 from one of the repos.

[marcusburghardt]

Could you provide more details about the differences between STIG and CIS regarding the audit_rules_suid_privilege_function rule, please?

STIG definition:

-a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid
-a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgid

CIS definition

-a always,exit -F arch=b32 -C euid!=uid -F auid!=unset -S execve -k user_emulation
-a always,exit -F arch=b64 -C euid!=uid -F auid!=unset -S execve -k user_emulation

STIG has focused on both uid and gid while CIS only cares about the uid. The reason why the CIS Workbench fails the analysis is the missing auid parameter and the euid=0.

Thanks for the context. I think this could also be resolved with variables instead of a new rule.
On the other hand, a new rule could also work but I would use a more generic name instead of fixing the benchmark name on it. Supposing the STIG adopts the same approach of CIS in the future, it would be weird to use a audit_rules_suid_privilege_function_cis rule for STIG. This is just an example.

Please, consider the introduction of a variable for this rule or renaming the new rule.

[Mackemania]

Could you provide more details about the differences between STIG and CIS regarding the audit_rules_suid_privilege_function rule, please?

STIG definition:

-a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid
-a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid
-a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgid

CIS definition

-a always,exit -F arch=b32 -C euid!=uid -F auid!=unset -S execve -k user_emulation
-a always,exit -F arch=b64 -C euid!=uid -F auid!=unset -S execve -k user_emulation

STIG has focused on both uid and gid while CIS only cares about the uid. The reason why the CIS Workbench fails the analysis is the missing auid parameter and the euid=0.

Thanks for the context. I think this could also be resolved with variables instead of a new rule. On the other hand, a new rule could also work but I would use a more generic name instead of fixing the benchmark name on it. Supposing the STIG adopts the same approach of CIS in the future, it would be weird to use a audit_rules_suid_privilege_function_cis rule for STIG. This is just an example.

Please, consider the introduction of a variable for this rule or renaming the new rule.

Thank you! I will change the name, we tried introducing variables, but since the benchmark isn't available when compiling the Jinja macros for the remidiations and documentation it became impossible.

[jan-cerny]

The fail on Fedora Rawhide is caused by OpenSCAP/openscap#1995 and isn't related to the contents of this PR.

[codeclimate]

Code Climate has analyzed commit 85f0389 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 52.8% (0.0% change).

View more on Code Climate.

[jan-cerny]

/packit test