CVE-2024-20363: Cisco Secure Firewall Threat Defense

Medium severity, CVSS 5.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Multiple Cisco products are affected by a vulnerability in the Snort Intrusion Prevention System (IPS) rule engine that could allow an unauthenticated, remote attacker to bypass the configured rules on an affected system. This vulnerability is due to incorrect HTTP packet handling. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network.

Affected products

• Cisco Secure Firewall Threat Defense: version 7.4.0 only
• Cisco Snort: from 3.0.0-233, before 3.1.69.0 (fixed in 3.1.69.0)
• Cisco Unified Threat Defense Snort Intrusion Prevention System Engine: version 17.6.4 only; version 17.6.5 only; version 17.12.1a only; version 17.12.2 only

Published 2024-05-22. Last modified 2026-08-11.