CVE-2021-24020 Weak cryptography in Fortinet FortiMail

What is CVE-2021-24020?

CVE-2021-24020 is a high-severity vulnerability in Fortinet FortiMail, published on 9 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A missing cryptographic step in the implementation of the hash digest algorithm in FortiMail 6.4.0 through 6.4.4, and 6.2.0 through 6.2.7 may allow an unauthenticated attacker to tamper with signed URLs by appending further data which allows bypass of signature verification.

Weakness: CWE-347

Which versions are affected by CVE-2021-24020?

It affects 1 product.

Products include Fortinet Fortimail.

How do I fix CVE-2021-24020?

No fix has been published for CVE-2021-24020 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-24020 being exploited?

There is no known exploitation of CVE-2021-24020 in the wild and no public exploit code.

Other vulnerabilities in Fortinet FortiMail

• CVE-2026-104286 Fortinet FortiMail Path Traversal Exploited Critical 9.8
• CVE-2021-36166 Auth bypass in Fortinet FortiMail Critical 9.8
• CVE-2021-24007 SQL injection in Fortinet FortiMail Critical 9.8
• CVE-2020-9294 Auth bypass in FortiMail Critical 9.8
• CVE-2023-47539 Auth bypass in FortiMail Critical 9.0

Sources

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

Also known as GHSA-8wr8-gr7j-v6cg.