Vulnerability Discussion
Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.
Check
Verify the SSH daemon does not allow GSSAPI authentication with the following command:
$ sudo grep -i GSSAPIAuthentication /etc/ssh/sshd_config
GSSAPIAuthentication no
If the value is returned as "yes", the returned line is commented out, no output is returned, or has not been documented with the ISSO, this is a finding.
Fix
Configure the SSH daemon to not allow GSSAPI authentication.
Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "no":
GSSAPIAuthentication no
The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command:
$ sudo systemctl restart sshd.service