CVE-2022-20757: Cisco Secure Firewall Threat Defense

High severity, CVSS 7.5. EPSS: 1.3% chance of exploitation in the next 30 days.

A vulnerability in the connection handling function in Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper traffic handling when platform limits are reached. An attacker could exploit this vulnerability by sending a high rate of UDP traffic through an affected device. A successful exploit could allow the attacker to cause all new, incoming connections to be dropped, resulting in a DoS condition.

Affected products

• Cisco Secure Firewall Threat Defense: before 6.4.0.15 (fixed in 6.4.0.15); from 6.5.0, before 6.6.5.2 (fixed in 6.6.5.2); from 6.7.0, before 7.0.2 (fixed in 7.0.2); version 7.1.0 only

Published 2022-05-03. Last modified 2026-08-11.