# CVE-2019-9804: Command injection in Firefox

> Attackers can execute arbitrary bash commands on macOS by tricking users into pasting a maliciously crafted URL copied from Firefox Developer Tools.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/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:** 26 Apr 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-448w-rf52-mp55, UBUNTU-CVE-2019-9804

## What is CVE-2019-9804?

CVE-2019-9804 is a critical command injection vulnerability in Mozilla Firefox, published on 26 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Firefox Developer Tools it is possible that pasting the result of the 'Copy as cURL' command into a command shell on macOS will cause the execution of unintended additional bash script commands if the URL was maliciously crafted. This is the result of an issue with the native version of Bash on macOS. *Note: This issue only affects macOS. Other operating systems are unaffected.*. This vulnerability affects Firefox < 66.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2019-9804?

It affects 1 product.


Products: Mozilla Firefox.

## How do I fix CVE-2019-9804?

Upgrade to a fixed version.

## Is CVE-2019-9804 being exploited?

There is no known exploitation of CVE-2019-9804 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-2019-9804 and fix it if it is affected.

What it is: CVE-2019-9804 is a critical command injection vulnerability in Mozilla Firefox, published on 26 Apr 2019. 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-2019-9804 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-2019-9804/ (Markdown: https://insights.sbomify.com/CVE-2019-9804/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-9804
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-9804
- OSV: https://osv.dev/vulnerability/CVE-2019-9804

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-9804/
Summaries are generated and may contain mistakes; the official description above is the record.