USN-4423-1: Firefox vulnerability

14 July 2020

A X-Frame-Options bypass was discovered in Firefox.



  • firefox - Mozilla Open Source web browser


It was discovered that X-Frame-Options could be bypassed in some
circumstances. If a user were tricked in to opening a specially crafted
website, an attacker could potentially exploit this to conduct
clickjacking attacks.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 20.04
Ubuntu 19.10
Ubuntu 18.04
Ubuntu 16.04

After a standard system update you need to restart Firefox to make
all the necessary changes.