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 no lines are returned, or the setting is set to yes, this is a finding.

Fix Text

Edit the SSH client configuration and set (add if necessary) a GSSAPIAuthentication directive set to no.

Additional Identifiers

Rule ID: SV-227903r603266_rule

Vulnerability ID: V-227903

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

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