The vulnerability is an authentication loophole in FortiOS versions 4.3.0 to 4.3.16 and 5.0.0 to 5.0.7. It was reported and patched in 2014 and was revived on Saturday after code for exploiting the vulnerability was posted to Full Disclosure.
With word of the exploit spreading through sources like Twitter, Fortinet issued a statement on Tuesday pointing out that the problem has been fixed. (Fortinet also went out of its way to claim the problem doesn’t count as a back door, instead calling it a “management authentication issue.”) Of course, not everybody updates software in a timely manner, or at all, so it’s reasonable to believe the exploit could still work on some installed systems.
The problem was not the result of any malicious activity, Fortinet noted.
That makes Fortinet’s case much less scary than the one Juniper recently addressed. In December, Juniper found what it claims was unauthorized code planted into ScreenOS, the operating system powering its firewalls. An attacker could use the code to gain access to the firewall and decrypt VPN traffic.
Just last week, Juniper announced it would remove the random-number generators that are at the root of the exploit.