CVE-2020-12819: Fortinet FortiOS

High severity, CVSS 7.5. EPSS: 0.8% chance of exploitation in the next 30 days.

A heap-based buffer overflow vulnerability in the processing of Link Control Protocol messages in FortiGate versions 5.6.12, 6.0.10, 6.2.4 and 6.4.1 and earlier may allow a remote attacker with valid SSL VPN credentials to crash the SSL VPN daemon by sending a large LCP packet, when tunnel mode is enabled. Arbitrary code execution may be theoretically possible, albeit practically very difficult to achieve in this context

Affected products

• Fortinet FortiOS: before 5.6.13 (fixed in 5.6.13); from 6.0.0, before 6.0.11 (fixed in 6.0.11); from 6.2.0, before 6.2.5 (fixed in 6.2.5); from 6.4.0, before 6.4.2 (fixed in 6.4.2)

Published 2024-12-19. Last modified 2026-06-17.