CVE-2020-12812

Name: CVE-2020-12812
Creator: NVD / NIST
Published: 2020-07-24T23:15:12.003+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 49.34%

Last modified Jun 17, 2026

CVE-2020-12812 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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 has confirmed active exploitation in the wild. EPSS estimates a 49.34% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

49.34%

98.7th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by May 3, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Fortinet	Fortios	< 6.0.10
Fortinet	Fortios	>= 6.2.0, < 6.2.4
Fortinet	Fortios	6.4.0

References

https://fortiguard.com/psirt/FG-IR-19-283Vendor Advisory
https://fortiguard.com/psirt/FG-IR-19-283Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-12812US Government Resource

Timeline

Published: Jul 24, 2020
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2020-12812?

How severe is CVE-2020-12812?

CVE-2020-12812 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 49.34% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2020-12812?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-12812?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST