# CVE-2016-5293: Path traversal in Firefox

> Local attackers can append data to arbitrary files via hardlink manipulation in the Mozilla Updater log on Windows.

- **Severity:** Medium 5.5 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Jun 2018
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-4m4x-qm8m-cxqj

## What is CVE-2016-5293?

CVE-2016-5293 is a medium-severity path traversal vulnerability in Debian Debian Linux, published on 11 Jun 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

When the Mozilla Updater is run, if the Updater's log file in the working directory points to a hardlink, data can be appended to an arbitrary local file. This vulnerability requires local system access. Note: this issue only affects Windows operating systems. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2016-5293?

It affects 2 products.


Products: Debian Debian Linux, Mozilla Firefox.

## How do I fix CVE-2016-5293?

Upgrade to a fixed version.

## Is CVE-2016-5293 being exploited?

There is no known exploitation of CVE-2016-5293 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-5293 and fix it if it is affected.

What it is: CVE-2016-5293 is a medium-severity path traversal vulnerability in Debian Debian Linux, published on 11 Jun 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-5293 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2016-5293/ (Markdown: https://insights.sbomify.com/CVE-2016-5293/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-5293
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-5293
- OSV: https://osv.dev/vulnerability/CVE-2016-5293

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-5293/
Summaries are generated and may contain mistakes; the official description above is the record.