CVE-2013-5476: Cisco IOS

High severity, CVSS 7.8. EPSS: 1.9% chance of exploitation in the next 30 days.

The Zone-Based Firewall (ZFW) feature in Cisco IOS 15.1 through 15.2, when content filtering or HTTP ALG inspection is enabled, allows remote attackers to cause a denial of service (device reload or hang) via crafted IPv4 HTTP traffic, aka Bug ID CSCtx56174.

Affected products

• Cisco IOS: version 15.1 only; version 15.2 only

Published 2013-09-27. Last modified 2026-06-16.