CVE-2021-4221

Publication date 22 December 2022

Last updated 25 August 2025


Ubuntu priority

Cvss 3 Severity Score

4.3 · Medium

Score breakdown

Description

If a domain name contained a RTL character, it would cause the domain to be rendered to the right of the path. This could lead to user confusion and spoofing attacks. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*<br>*Note*: Due to a clerical error this advisory was not included in the original announcement, and was added in Feburary 2022. This vulnerability affects Firefox < 92.

Read the notes from the security team

Status

Package Ubuntu Release Status
firefox 22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty Ignored end of standard support

Notes


mdeslaur

starting with Ubuntu 22.04, the firefox package is just a script that installs the Firefox snap


alexmurray

Only affects Firefox for Android

Severity score breakdown

Parameter Value
Base score 4.3 · Medium
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Scope Unchanged
Confidentiality None
Integrity impact Low
Availability impact None
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N