Title

The Red Hat Enterprise Linux operating system must audit all uses of the unix_chkpwd 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 "unix_chkpwd" command occur. Check the file system rule in "/etc/audit/audit.rules" with the following command: $ sudo grep -w "/usr/sbin/unix_chkpwd" /etc/audit/audit.rules -a always,exit -F path=/usr/sbin/unix_chkpwd -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 "unix_chkpwd" command occur. Add or update the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/unix_chkpwd -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-204543r861029_rule

Vulnerability ID: V-204543

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

Expert Comments

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