Information
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
Solution
Configure the Ubuntu operating system to use multifactor authentication for network access to accounts.
Add or update 'pam_pkcs11.so' in '/etc/pam.d/common-auth' to match the following line:
auth [success=2 default=ignore] pam_pkcs11.so
Set the sshd option 'PubkeyAuthentication yes' in the '/etc/ssh/sshd_config' file.