What’s Vulnerable › Vulnerabilities
CVE-2021-24020
- Severity: critical (CVSS 9.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.6% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-07-09 · updated 2026-06-17
- Weakness: CWE-347
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.
Affected products
- Fortinet FortiMail: from 6.2.0 through 6.2.7; from 6.4.0 before 6.4.5 — fixed in 6.4.5
How to fix
Upgrade to a fixed version: Fortinet FortiMail 6.4.5. Check the vendor advisory for mitigations.
References
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