USN-4353-1 caused a regression in Firefox.
USN-4353-1 fixed vulnerabilities in Firefox. The update caused a regression that impaired the functionality of some addons. This update fixes the problem.
12 May 2020
A security issue affects these releases of Ubuntu and its derivatives:
USN-4353-1 caused a regression in Firefox.
USN-4353-1 fixed vulnerabilities in Firefox. The update caused a regression that impaired the functionality of some addons. This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, bypass security restrictions, spoof the URL bar, or execute arbitrary code. (CVE-2020-6831, CVE-2020-12387, CVE-2020-12390, CVE-2020-12391, CVE-2020-12394, CVE-2020-12395, CVE-2020-12396)
It was discovered that the Devtools’ ‘Copy as cURL’ feature did not properly HTTP POST data of a request. If a user were tricked in to using the ‘Copy as cURL’ feature to copy and paste a command with specially crafted data in to a terminal, an attacker could potentially exploit this to obtain sensitive information from local files. (CVE-2020-12392)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to restart Firefox to make all the necessary changes.