A Firefox security update has been released for Ubuntu Linux 20.04 LTS.

[USN-6367-1] Firefox vulnerability

==========================================================================
Ubuntu Security Notice USN-6367-1
September 14, 2023

firefox vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

Firefox could be made to crash or run programs if it opened a malicious
website.

Software Description:
- firefox: Mozilla Open Source web browser

Details:

It was discovered that Firefox did not properly manage memory when handling
WebP images. If a user were tricked into opening a webpage containing
malicious WebP image file, an attacker could potentially exploit these to
cause a denial of service or execute arbitrary code. (CVE-2023-4863)

Update instructions:

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

Ubuntu 20.04 LTS:
firefox 117.0.1+build2-0ubuntu0.20.04.1

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

References:
https://ubuntu.com/security/notices/USN-6367-1
CVE-2023-4863

Package Information:
https://launchpad.net/ubuntu/+source/firefox/117.0.1+build2-0ubuntu0.20.04.1