A local privilege escalation and local code execution vulnerability in Fortinet FortiOS 5.6.0 to 5.6.2, 5.4.0 to 5.4.8, and 5.2 and below versions allows attacker to execute unauthorized binary program contained on an USB drive plugged into a FortiGate via linking the aforementioned binary program to a command that is allowed to be run by the fnsysctl CLI command.
https://fortiguard.com/advisory/FG-IR-17-245