CVE-2020-3317: Cisco Secure Firewall Threat Defense

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

A vulnerability in the ssl_inspection component of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to crash Snort instances. The vulnerability is due to insufficient input validation in the ssl_inspection component. An attacker could exploit this vulnerability by sending a malformed TLS packet through a Cisco Adaptive Security Appliance (ASA). A successful exploit could allow the attacker to crash a Snort instance, resulting in a denial of service (DoS) condition.

Affected products

• Cisco Secure Firewall Threat Defense: before 6.4.0.10 (fixed in 6.4.0.10); from 6.5.0, before 6.5.0.5 (fixed in 6.5.0.5)

Published 2020-10-21. Last modified 2026-08-11.