# CVE-2018-12397: Security feature bypass in Firefox

> WebExtensions can access local files without user permission warnings, bypassing security prompts in Firefox.

- **Severity:** High 7.1 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 28 Feb 2019
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-12397, GHSA-xxh5-92qj-c4gh, UBUNTU-CVE-2018-12397

## What is CVE-2018-12397?

CVE-2018-12397 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 28 Feb 2019. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A WebExtension can request access to local files without the warning prompt stating that the extension will "Access your data for all websites" being displayed to the user. This allows extensions to run content scripts in local pages without permission warnings when a local file is opened. This vulnerability affects Firefox ESR < 60.3 and Firefox < 63.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2018-12397?

It affects 7 products.


Products: Canonical Ubuntu Linux, Debian Debian Linux, Mozilla Firefox, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Eus, Redhat Enterprise Linux Workstation.

## How do I fix CVE-2018-12397?

Upgrade to a fixed version.

## Is CVE-2018-12397 being exploited?

There is no known exploitation of CVE-2018-12397 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-12397 and fix it if it is affected.

What it is: CVE-2018-12397 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 28 Feb 2019. 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-2018-12397 in the wild and no public exploit code.

Affected product: Canonical Ubuntu 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-2018-12397/ (Markdown: https://insights.sbomify.com/CVE-2018-12397/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-12397
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-12397
- OSV: https://osv.dev/vulnerability/CVE-2018-12397

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-12397/
Summaries are generated and may contain mistakes; the official description above is the record.