AlmaLinux OS 9 must map the authenticated identity to the user or group account for PKI-based authentication.

STIG ID: ALMA-09-038960  |  SRG: SRG-OS-000068-GPOS-00036 |  Severity: medium |  CCI: CCI-000187 |  Vulnerability Id: V-269411

Vulnerability Discussion

Without mapping the certificate used to authenticate to the user account, the ability to determine the identity of the individual user or group will not be available for forensic analysis.

Check

Note: If the system administrator (SA) demonstrates the use of an approved alternate multifactor authentication method, this requirement is not applicable.

Verify the operating system implements Online Certificate Status Protocol (OCSP) and is using the proper digest value on the system with the following command:

$ grep certmap /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf

/etc/sssd/conf.d/mapping.conf:[certmap/testing.test/rule_name]

If the certmap section does not exist, ask the system administrator (SA) to indicate how certificates are mapped to accounts. If there is no evidence of certificate mapping, this is a finding.

Fix

Configure AlmaLinux OS 9 to map the authenticated identity to the user or group account by adding or modifying the certmap section of the "/etc/sssd/sssd.conf" file or a "*.conf" file within the "/etc/sssd/conf.d/" directory, based on the following example:

[certmap/testing.test/rule_name]
matchrule = .*EDIPI@mil
maprule = (userCertificate;binary={cert!bin})
domains = testing.test

The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command:

$ systemctl restart sssd.service