SSH MITM deep inspection
Due to an increase in recent years of vulnerabilities discovered in the SSH protocol, protections have been incorporated into FortiOS's Intrusion Prevention System (IPS) engine that will aid in protecting against malicious activity coming through the FortiGate against SSH access points. In addition to the protections offered by IPS, additional settings and functionality have been added to protect against man-in-the-middle (MITM) attacks that use SSH as the attack vector.
For more information, see SSH MITM deep inspection.