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V-219163

CAT III (Low)

The Ubuntu operating system must be configured such that Pluggable Authentication Module (PAM) prohibits the use of cached authentications after one day.

Rule ID

SV-219163r958828_rule

STIG

Canonical Ubuntu 18.04 LTS Security Technical Implementation Guide

Version

V2R15

CCIs

CCI-002007

Discussion

If cached authentication information is out-of-date, the validity of the authentication information may be questionable.

Check Content

If smart card authentication is not being used on the system this item is Not Applicable.

Verify that Pluggable Authentication Module (PAM) prohibits the use of cached authentications after one day.

Check that PAM prohibits the use of cached authentications after one day with the following command:

# sudo grep offline_credentials_expiration /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf

offline_credentials_expiration = 1

If "offline_credentials_expiration" is not set to a value of "1", in /etc/sssd/sssd.conf or in a file with a name ending in .conf in the /etc/sssd/conf.d/ directory, this is a finding.

Fix Text

Configure Pluggable Authentication Module (PAM) to prohibit the use of cached authentications after one day. Add or change the following line in "/etc/sssd/sssd.conf" just below the line "[pam]".

offline_credentials_expiration = 1

Note: It is valid for this configuration to be in a file with a name that ends with ".conf" and does not begin with a "." in the /etc/sssd/conf.d/ directory instead of the /etc/sssd/sssd.conf file.