CVE-2009-2872: Cisco IOS

Medium severity, CVSS 6.8. EPSS: 2.3% chance of exploitation in the next 30 days.

Cisco IOS 12.0 through 12.4, when IP-based tunnels and the Cisco Express Forwarding feature are enabled, allows remote attackers to cause a denial of service (device reload) via a malformed packet that is not properly handled during switching from one tunnel to a second tunnel, aka Bug IDs CSCsh97579 and CSCsq31776.

Affected products

• Cisco IOS: version 12.0 only; version 12.0da only; version 12.0db only; version 12.0dc only; version 12.0s only; version 12.0sc only; …

Published 2009-09-28. Last modified 2026-06-16.