CVE-2005-2451: Cisco IOS

Low severity, CVSS 2.1. EPSS: 1.4% chance of exploitation in the next 30 days.

Cisco IOS 12.0 through 12.4 and IOS XR before 3.2, with IPv6 enabled, allows remote attackers on a local network segment to cause a denial of service (device reload) and possibly execute arbitrary code via a crafted IPv6 packet.

Affected products

• Cisco IOS: version 12.0s only; version 12.0sl only; version 12.0st only; version 12.0sy only; version 12.1xu only; version 12.1xv only; …
• Cisco IOS XR: version 3.0.1 only; version 3.1.0 only

Published 2005-08-03. Last modified 2026-06-16.