# CVE-2020-6830: Information disclosure in Firefox for iOS

> Firefox for iOS leaked a security token used for native-to-JS bridging, allowing potential bypass of bridging restrictions.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 May 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-3j75-7jc2-vqcg

## What is CVE-2020-6830?

CVE-2020-6830 is a high-severity vulnerability in Mozilla Firefox Mobile, published on 26 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

For native-to-JS bridging, the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token was being used for JS-to-native also, but it isn't needed in this case, and its usage was also leaking this token. This vulnerability affects Firefox for iOS < 25.

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

## Which versions are affected by CVE-2020-6830?

It affects 1 product.


Products: Mozilla Firefox Mobile.

## How do I fix CVE-2020-6830?

No fix has been published for CVE-2020-6830 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-6830 being exploited?

There is no known exploitation of CVE-2020-6830 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Firefox Mobile

- [CVE-2026-84135](https://insights.sbomify.com/CVE-2026-84135/): Other issue in Firefox Focus for Android (critical 9.8)
- [CVE-2024-43111](https://insights.sbomify.com/CVE-2024-43111/): Cross-site scripting in Firefox for iOS (critical 9.8)
- [CVE-2023-49060](https://insights.sbomify.com/CVE-2023-49060/): Information disclosure in Firefox for iOS (critical 9.8)
- [CVE-2026-92033](https://insights.sbomify.com/CVE-2026-92033/): Privilege escalation in Firefox for Android (high 8.8)
- [CVE-2026-84117](https://insights.sbomify.com/CVE-2026-84117/): Privilege escalation in Firefox for Android (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-6830 and fix it if it is affected.

What it is: CVE-2020-6830 is a high-severity vulnerability in Mozilla Firefox Mobile, published on 26 May 2020. 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-2020-6830 in the wild and no public exploit code.

Affected product: Mozilla Firefox Mobile. 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-2020-6830/ (Markdown: https://insights.sbomify.com/CVE-2020-6830/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-6830
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-6830
- OSV: https://osv.dev/vulnerability/CVE-2020-6830

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-6830/
Summaries are generated and may contain mistakes; the official description above is the record.