CVE-2021-36166 Auth bypass in Fortinet FortiMail

Critical 9.8 Published 1 Mar 2022 Updated 25 Oct 2024

Remote attackers can guess administrative authentication tokens by observing system properties, leading to unauthorized access to FortiMail.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-36166?

CVE-2021-36166 is a critical authentication bypass vulnerability in Fortinet FortiMail, published on 1 Mar 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An improper authentication vulnerability in FortiMail before 7.0.1 may allow a remote attacker to efficiently guess one administrative account's authentication token by means of the observation of certain system's properties.

Weakness: CWE-330

Which versions are affected by CVE-2021-36166?

It affects 1 product.

Products include Fortinet Fortimail.

How do I fix CVE-2021-36166?

No fix has been published for CVE-2021-36166 yet. Limit exposure of the affected software until one is available.

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

Is CVE-2021-36166 being exploited?

There is no known exploitation of CVE-2021-36166 in the wild and no public exploit code.

Sources

Also known as GHSA-6gm4-rphq-fcfx.