Details

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.

Solution

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

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_CAN_Ubuntu_20-04_LTS_V1R1_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Maintenance.This control applies to the following type of system Unix.

References

• 800-53|MA-4c.
• CAT|II
• CCI|CCI-000877
• Rule-ID|SV-238211r653808_rule
• STIG-ID|UBTU-20-010035
• Vuln-ID|V-238211

Source

• Tenable.com/audits