# CVE-2009-3376: Other in n/a

> Remote attackers can spoof file extensions in downloads using Unicode characters, potentially tricking users into executing malicious files.

- **Severity:** Critical 9.3 (`AV:N/AC:M/Au:N/C:C/I:C/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 29 Oct 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-xgrc-85pp-86cg

## What is CVE-2009-3376?

CVE-2009-3376 is a critical vulnerability in Mozilla Firefox, published on 29 Oct 2009. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-16

## Which versions are affected by CVE-2009-3376?

It affects 2 products.


Products: Mozilla Firefox, Mozilla Seamonkey.

## How do I fix CVE-2009-3376?

Upgrade to a fixed version.

## Is CVE-2009-3376 being exploited?

There is no known exploitation of CVE-2009-3376 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Firefox

- [CVE-2019-11708](https://insights.sbomify.com/CVE-2019-11708/): Mozilla Firefox and Thunderbird Sandbox Escape (critical 10.0, exploited in the wild)
- [CVE-2010-3765](https://insights.sbomify.com/CVE-2010-3765/): Mozilla Multiple Products Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2022-26486](https://insights.sbomify.com/CVE-2022-26486/): Mozilla Firefox Use-After-Free (critical 9.6, exploited in the wild)
- [CVE-2022-26485](https://insights.sbomify.com/CVE-2022-26485/): Mozilla Firefox Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2019-11707](https://insights.sbomify.com/CVE-2019-11707/): Mozilla Firefox and Thunderbird Type Confusion (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-3376 and fix it if it is affected.

What it is: CVE-2009-3376 is a critical vulnerability in Mozilla Firefox, published on 29 Oct 2009. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2009-3376 in the wild and no public exploit code.

Affected product: Mozilla Firefox. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2009-3376/ (Markdown: https://insights.sbomify.com/CVE-2009-3376/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-3376
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-3376
- OSV: https://osv.dev/vulnerability/CVE-2009-3376

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-3376/
Summaries are generated and may contain mistakes; the official description above is the record.