CVE-2009-2872

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a login. High risk of service disruption.

Exploit odds

2.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2009-09-28 19:30 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-16 23:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.3% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2009-09-28 19:30 UTC

Last modified

2026-06-16 23:10 UTC

Exploit probability

2.3% · EPSS, next 30 days

Record status

Modified

Affected

• Cisco iOS 12.0
• Cisco iOS 12.0da
• Cisco iOS 12.0db
• Cisco iOS 12.0dc
• Cisco iOS 12.0s
• Cisco iOS 12.0sc
• Cisco iOS 12.0sl
• Cisco iOS 12.0sp

Attack profile CVSS 2.0 · 6.8

Attack vector

Network

Complexity

Low

Authentication

Single

Confidentiality

None

Integrity

None

Availability

Complete

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2009-2872.md and follow it. Check whether this project is affected by CVE-2009-2872. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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