Vulnerability Discussion
The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access.
DOD has mandated the use of the common access card (CAC) to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems.
Check
Verify Ubuntu 22.04 LTS electronically verifies PIV credentials via certificate status checking by using the following command:
$ sudo grep use_pkcs11_module /etc/pam_pkcs11/pam_pkcs11.conf | awk '/pkcs11_module opensc {/,/}/' /etc/pam_pkcs11/pam_pkcs11.conf | grep cert_policy | grep ocsp_on
cert_policy = ca,signature,ocsp_on;
If every returned "cert_policy" line is not set to "ocsp_on", the line is commented out, or is missing, this is a finding.
Fix
Configure Ubuntu 22.04 LTS to do certificate status checking for multifactor authentication.
Add or modify all "cert_policy" lines in the "/etc/pam_pkcs11/pam_pkcs11.conf" file with the following:
ocsp_on