CVE-2020-3304: Cisco Adaptive Security Appliance

High severity, CVSS 8.6. EPSS: 3.9% chance of exploitation in the next 30 days.

A vulnerability in the web interface of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition. Note: This vulnerability applies to IP Version 4 (IPv4) and IP Version 6 (IPv6) HTTP traffic.

Affected products

• Cisco Adaptive Security Appliance: before 9.6.4.45 (fixed in 9.6.4.45)
• Cisco Adaptive Security Appliance Software: from 9.8.0, before 9.8.4.22 (fixed in 9.8.4.22); from 9.9.0, before 9.9.2.80 (fixed in 9.9.2.80); from 9.10.0, before 9.10.1.44 (fixed in 9.10.1.44); from 9.12.0, before 9.12.3.12 (fixed in 9.12.3.12); from 9.13.0, before 9.13.1.12 (fixed in 9.13.1.12); from 9.14.0, before 9.14.1.10 (fixed in 9.14.1.10)
• Cisco Secure Firewall Threat Defense: before 6.3.0.6 (fixed in 6.3.0.6); from 6.4.0, 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); from 6.6.0, before 6.6.1 (fixed in 6.6.1)

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