RHEL 9 audit system must protect logon UIDs from unauthorized change.

Documentable No

Rule ID SV-258228r991572_rule

CCI References

CCI-000162CCI-000163CCI-000164CCI-000172

Discussion

If modification of login user identifiers (UIDs) is not prevented, they can be changed by nonprivileged users and make auditing complicated or impossible. Satisfies: SRG-OS-000462-GPOS-00206, SRG-OS-000475-GPOS-00220, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029

Check Procedure

Verify the audit system prevents unauthorized changes to logon UIDs with the following command:

$ sudo grep -i immutable /etc/audit/audit.rules

--loginuid-immutable

If the "--loginuid-immutable" option is not returned in the "/etc/audit/audit.rules", or the line is commented out, this is a finding.

Fix Action

Configure RHEL 9 auditing to prevent modification of login UIDs once they are set by adding the following line to /etc/audit/rules.d/audit.rules:

--loginuid-immutable

The audit daemon must be restarted for the changes to take effect.