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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-238201	UBTU-20-010006	SV-238201r958452_rule		High

Description

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.

STIG	Date
Canonical Ubuntu 20.04 LTS Security Technical Implementation Guide	2025-05-16

Details

Check Text (C-41411r832932_chk)

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.

Fix Text (F-41370r653777_fix)

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".