The Ubuntu operating system must map the authenticated identity to the user or group account for PKI-based authentication.

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.

Verify that "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 the list does not contain "pwent" this is a finding.

Set "use_mappers=pwent" in "/etc/pam_pkcs11/pam_pkcs11.conf" or, if there is already a comma-separated list of mappers, add it to the list, separated by comma, and before the null mapper.

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".