FortiOS
CVE-2020-12812: FortiOS SSL VPN Improper Authentication
An improper authentication vulnerability in SSL VPN in FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below may result in a user being able to log in successfully without being prompted for the second factor of authentication (FortiToken) if they changed the case of their username.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Fortinet FortiOS FortiOS 6.4 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An improper authentication vulnerability in SSL VPN in FortiOS 6.4.0, 6.2.0 to 6.2.3, 6.0.9 and below may result in a user being able to log in successfully without being prompted for the second factor of authentication (FortiToken) if they changed the case of their username.
Exploitation
CISA lists this CVE as exploited in the wild since 3 Nov 2021, including in ransomware campaigns.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 10 Oct 2026.