November 3, 2021 · Applied Cybernetics Group
CVE-2020-12812 — Fortinet FortiOS
known ransomware use
Fortinet FortiOS SSL VPN Improper Authentication Vulnerability
- Added to KEV
2021-11-03- Federal due date
2022-05-03- Vendor
- Fortinet
- Product
- FortiOS
- EPSS
- 98.8th percentile (score 0.493, as of
2026-07-13) - NVD CVSS v3.1
- —
- Ransomware use
- Known
- ATT&CK
- T1556 · signal rollup
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2020-12812
CISA short description
Fortinet FortiOS SSL VPN contains an improper authentication vulnerability that may allow a user to login successfully without being prompted for the second factor of authentication (FortiToken) if they change the case in their username.
Required action
Apply updates per vendor instructions.