CVE-2021-24018: Fortinet FortiOS

High severity, CVSS 8.8. EPSS: 1% chance of exploitation in the next 30 days.

A buffer underwrite vulnerability in the firmware verification routine of FortiOS before 7.0.1 may allow an attacker located in the adjacent network to potentially execute arbitrary code via a specifically crafted firmware image.

Affected products

• Fortinet FortiOS: before 6.2.10 (fixed in 6.2.10); from 6.4.0, before 6.4.7 (fixed in 6.4.7); version 7.0.0 only

Published 2021-08-04. Last modified 2026-06-17.