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
Verify the Ubuntu operating system has the "libpam-pkcs11" package installed, by running the following command:
# dpkg -l | grep libpam-pkcs11
If "libpam-pkcs11" is not installed, this is a finding.
Check if use_mappers is set to pwent in /etc/pam_pkcs11/pam_pkcs11.conf file
# grep use_mappers /etc/pam_pkcs11/pam_pkcs11.conf
use_mappers = pwent
If "use_mappers" is not found, or is not set to "pwent", this is a finding.
Fix
Install libpam-pkcs11 package on the system.
Set use_mappers=pwent in /etc/pam_pkcs11/pam_pkcs11.conf
If the system is missing an "/etc/pam_pkcs11/" directory and an "/etc/pam_pkcs11/pam_pkcs11.conf", find an example to copy into place and modify accordingly at "/usr/share/doc/libpam-pkcs11/examples/pam_pkcs11.conf.example.gz".