Vulnerability Discussion

Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased.

Multifactor authentication requires using two or more factors to achieve authentication.

Factors include:
1) something a user knows (e.g., password/PIN);
2) something a user has (e.g., cryptographic identification device, token); and
3) something a user is (e.g., biometric).

A privileged account is defined as an information system account with authorizations of a privileged user.

Network access is defined as access to an information system by a user (or a process acting on behalf of a user) communicating through a network (e.g., local area network, wide area network, or the internet).

The DOD CAC with DOD-approved PKI is an example of multifactor authentication.

Satisfies: SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055, SRG-OS-000377-GPOS-00162

Check

Verify the Ubuntu operating system uses multifactor authentication for local access to accounts.

Check that the "pam_pkcs11.so" option is configured in the "/etc/pam.d/common-auth" file with the following command:

# grep pam_pkcs11.so /etc/pam.d/common-auth
auth [success=2 default=ignore] pam_pkcs11.so

If "pam_pkcs11.so" is not set in "/etc/pam.d/common-auth", this is a finding.

Fix

Configure the Ubuntu operating system to use multifactor authentication for local access to accounts.

Add or update the following line in "/etc/pam.d/common-auth", placing it above any lines containing "pam_unix.so":

auth [success=2 default=ignore] pam_pkcs11.so