Fortinet · FortiOS
CVE-2020-12812
Fortinet FortiOS SSL VPN Improper Authentication Vulnerability
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.
CISA: 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.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: May 3, 2022
- Added to the CISA list
- November 3, 2021
- Published
- July 24, 2020
- Severity
- High 7.5 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- 45% in the top 1.2% of all known vulnerabilities
- Weakness
- CWE-178 CWE-287
- More details
- NVD · CVE.org · CISA
All references (1)
More exploited flaws from Fortinet
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jul 27, 2026 | Exposure of Sensitive Information to an Unauthorized Actor | FortiOS | Medium 5.3 | 29% |
| Jun 25, 2025 | Use of Hard-Coded Credentials | FortiOS | Medium 6.5 | 6.6% |
| Feb 9, 2024 | Out-of-Bound Write | FortiOS | Critical 9.6 | 85% |
| Mar 14, 2023 | Path Traversal | FortiOS | Medium 6.5 | 11% |
| Dec 13, 2022 | Heap-Based Buffer Overflow | FortiOS | Critical 9.3 | 99.5% |
| Dec 10, 2021 | Arbitrary File Download | FortiOS | Low 3.3 | 0.9% |
| Nov 3, 2021 | Default Configuration | FortiOS | Medium 6.5 | 19% |
| Nov 3, 2021 | SSL VPN Path Traversal | FortiOS | Critical 9.1 | >99.9% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.