CVE-2024-20508: Cisco Unified Threat Defense Snort Intrusion Prevention System Engine

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

A vulnerability in Cisco Unified Threat Defense (UTD) Snort Intrusion Prevention System (IPS) Engine for Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass configured security policies or cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of HTTP requests when they are processed by Cisco UTD Snort IPS Engine. An attacker could exploit this vulnerability by sending a crafted HTTP request through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process. If the action in case of Cisco UTD Snort IPS Engine failure is set to the default, fail-open, successful exploitation of this vulnerability could allow the attacker to bypass configured security policies. If the action in case of Cisco UTD Snort IPS Engine failure is set to fail-close, successful exploitation of this vulnerability could cause traffic that is configured to be inspected by Cisco UTD Snort IPS Engine to be dropped.

Affected products

• Cisco Unified Threat Defense Snort Intrusion Prevention System Engine: version 17.6.1a only; version 17.6.2 only; version 17.6.6 only; version 17.7.1a only; version 17.7.2 only; version 17.8.1a only; …

Published 2024-09-25. Last modified 2026-06-17.