CVE-2020-12812 Fortinet FortiOS SSL VPN Improper Authentication

What is CVE-2020-12812?

CVE-2020-12812 is a high-severity authentication bypass vulnerability in Fortinet Fortios, published on 24 Jul 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-178, CWE-287

Which versions are affected by CVE-2020-12812?

It affects 1 product.

Products include Fortinet Fortios.

How do I fix CVE-2020-12812?

No fix has been published for CVE-2020-12812 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2020-12812 being exploited?

Yes. Attackers have exploited CVE-2020-12812 in the wild since at least 3 Nov 2021, including in ransomware campaigns.

Other vulnerabilities in Fortinet Fortios

• CVE-2024-23113 Fortinet Multiple Products Format String Exploited Critical 9.8
• CVE-2022-40684 Fortinet Multiple Products Authentication Bypass Exploited Critical 9.8
• CVE-2024-55591 Fortinet FortiOS and FortiProxy Authentication Bypass Exploited Critical 9.6
• CVE-2024-21762 Fortinet FortiOS Out-of-Bound Write Exploited Critical 9.6
• CVE-2022-42475 Fortinet FortiOS Heap-Based Buffer Overflow Exploited Critical 9.3

All Fortinet Fortios vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-r9cj-q2hj-hfq9.