Title

The Ubuntu operating system must use strong authenticators in establishing nonlocal maintenance and diagnostic sessions. (Cat II impact)

Discussion

Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the Internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. Typically, strong authentication requires authenticators that are resistant to replay attacks and employ multifactor authentication. Strong authenticators include, for example, PKI where certificates are stored on a token protected by a password, passphrase, or biometric.

Check Content

Verify the Ubuntu operating system is configured to use strong authenticators in the establishment of nonlocal maintenance and diagnostic maintenance. Check that "UsePAM" is set to yes in /etc/ssh/sshd_config: # grep UsePAM /etc/ssh/sshd_config UsePAM yes If "UsePAM" is not set to "yes", this is a finding.

Fix Text

Configure the Ubuntu operating system to use strong authentication when establishing nonlocal maintenance and diagnostic sessions. Add or modify the following line to /etc/ssh/sshd_config UsePAM yes

Additional Identifiers

Rule ID: SV-219309r877395_rule

Vulnerability ID: V-219309

Group Title: SRG-OS-000125-GPOS-00065

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.