Nutanix OS must prevent SSH from permitting Generic Security Service Application Program Interface (GSSAPI) authentication.

Failure to provide logical access restrictions associated with changes to system configuration may have significant effects on the overall security of the system. When dealing with access restrictions pertaining to change control, it should be noted that any changes to the hardware, software, and/or firmware components of the operating system can have significant effects on the overall security of the system. Accordingly, only qualified and authorized individuals should be allowed to obtain access to operating system components for the purposes of initiating changes, including upgrades and modifications. Logical access restrictions include, for example, controls that restrict access to workflow automation, media libraries, abstract layers (e.g., changes implemented into third-party interfaces rather than directly into information systems), and change windows (e.g., changes occur only during specified times, making unauthorized changes easy to discover).

Verify Nutanix OS enforces access restrictions. Check that the SSH daemon does not permit GSSAPI authentication using the following command. $ sudo grep -i gssapiauth /etc/ssh/sshd_config GSSAPIAuthentication no If the "GSSAPIAuthentication" keyword is missing, is set to "yes" and is not documented with the information system security officer (ISSO), or the returned line is commented out, this is a finding.

Configure SSH to not permit GSSAPI authentication using the following command. $ sudo salt-call state.sls security/CVM/sshdCVM $ sudo systemctl restart sshd