Title

The SSH client must not permit GSSAPI authentication unless needed. (Cat III impact)

Discussion

GSSAPI authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system’s GSSAPI to remote hosts, increasing the attack surface of the system. GSSAPI authentication must be disabled unless needed.

Check Content

Check the SSH clients configuration for the GSSAPI authentication setting. # grep -i GSSAPIAuthentication /etc/ssh/ssh_config | grep -v '^#' If the setting is present and set to "yes", this is a finding. If the setting is absent or set to "no", this is not a finding.

Fix Text

Edit the /etc/ssh/ssh_config file and remove the GSSAPIAuthentication setting or change the GSSAPIAuthentication setting to "no".

Additional Identifiers

Rule ID: SV-40715r1_rule

Vulnerability ID: V-22474

Group Title: GEN005525

Expert Comments

CCIs tied to check.

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