CVE-2021-24012: Fortinet FortiOS

High severity, CVSS 7.3. EPSS: 0.5% chance of exploitation in the next 30 days.

An improper following of a certificate's chain of trust vulnerability in FortiGate versions 6.4.0 to 6.4.4 may allow an LDAP user to connect to SSLVPN with any certificate that is signed by a trusted Certificate Authority.

Affected products

• Fortinet FortiOS: from 6.4.0, before 6.4.5 (fixed in 6.4.5)

Published 2021-06-02. Last modified 2026-06-17.