---
id: CVE-2020-12812
title: >-
  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
  t…
summary: >-
  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
  t…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-178
  - CWE-287
  - CWE-287
vendor: fortinet
product: fortios
affected:
  - fortios < 6.0.10
  - 'fortios >= 6.2.0, < 6.2.4'
  - fortios = 6.4.0
patched:
  - fortios 6.2.4
published: '2020-07-24'
updated: '2026-08-12'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-12812'
references:
  - url: 'https://fortiguard.com/psirt/FG-IR-19-283'
    label: psirt@fortinet.com
  - url: 'https://fortiguard.com/psirt/FG-IR-19-283'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-12812
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - kev
  - in-the-wild
epss: 0.49344
epssPercentile: 0.9885
kev: true
kevDateAdded: '2021-11-03'
kevDueDate: '2022-05-03'
kevRansomware: true
exploited: true
ingestedAt: '2026-08-12T05:52:07.582Z'
---

## Overview

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.

## Affected

- `fortios < 6.0.10`
- `fortios >= 6.2.0, < 6.2.4`
- `fortios = 6.4.0`

## Remediation

Upgrade past the affected range:

- `fortios 6.2.4`