Vulnerability Discussion

Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information.

At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise.

Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215

Check

Verify the SUSE operating system generates an audit record for all uses of the "ssh-keysign" command.

Check that the command is being audited by performing the following command:

> sudo auditctl -l | grep -w '/usr/lib/ssh/ssh-keysign'

-a always,exit -S all -F path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=-1 -k privileged-ssh-keysign

If the command does not return any output, this is a finding.

Note:
The "-k" allows for specifying an arbitrary identifier. The string following "-k" does not need to match the example output above.

Fix

Configure the SUSE operating system to generate an audit record for all uses of the "ssh-keysign" command.

Add or update the following rules in the "/etc/audit/rules.d/audit.rules" file:

-a always,exit -F path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=4294967295 -k privileged-ssh-keysign

To reload the rules file, restart the audit daemon

> sudo systemctl restart auditd.service

or issue the following command:

> sudo augenrules --load