---
id: CVE-2020-6830
title: >-
  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
summary: >-
  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 als…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-200
vendor: mozilla
product: firefox_mobile
affected:
  - firefox_mobile < 25.0
patched:
  - firefox_mobile 25.0
published: '2020-05-26'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-6830'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1632387'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2020-15/'
    label: security@mozilla.org
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1632387'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.mozilla.org/security/advisories/mfsa2020-15/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00903
epssPercentile: 0.57736
ingestedAt: '2026-08-19T15:41:14.003Z'
---

## Overview

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.

## Affected

- `firefox_mobile < 25.0`

## Remediation

Upgrade past the affected range:

- `firefox_mobile 25.0`