Title

The Red Hat Enterprise Linux operating system must audit all uses of the userhelper command. (Cat II impact)

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 password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215

Check Content

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "userhelper" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/userhelper" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd If the command does not return any output, this is a finding.

Fix Text

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "userhelper" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd The audit daemon must be restarted for the changes to take effect.

Additional Identifiers

Rule ID: SV-204546r861038_rule

Vulnerability ID: V-204546

Group Title: SRG-OS-000042-GPOS-00020

Expert Comments

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