# CVE-2018-12368: Security feature bypass in Firefox

> Attackers can execute arbitrary code on Windows 10 by bypassing Mark of the Web warnings for SettingContent-ms files via Firefox or Thunderbird.

- **Severity:** High 8.1 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-ghmm-93ww-fvhh

## What is CVE-2018-12368?

CVE-2018-12368 is a high-severity vulnerability in Mozilla Firefox, published on 18 Oct 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Windows 10 does not warn users before opening executable files with the SettingContent-ms extension even when they have been downloaded from the internet and have the "Mark of the Web." Without the warning, unsuspecting users unfamiliar with this new file type might run an unwanted executable. This also allows a WebExtension with the limited downloads.open permission to execute arbitrary code without user interaction on Windows 10 systems. *Note: this issue only affects Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

## Which versions are affected by CVE-2018-12368?

It affects 3 products.


Products: Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird.

## How do I fix CVE-2018-12368?

Upgrade to a fixed version.

## Is CVE-2018-12368 being exploited?

There is no known exploitation of CVE-2018-12368 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-2018-12368 and fix it if it is affected.

What it is: CVE-2018-12368 is a high-severity vulnerability in Mozilla Firefox, published on 18 Oct 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-12368 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-2018-12368/ (Markdown: https://insights.sbomify.com/CVE-2018-12368/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-12368
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-12368
- OSV: https://osv.dev/vulnerability/CVE-2018-12368

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-12368/
Summaries are generated and may contain mistakes; the official description above is the record.