Ubuntu 21.10 USN-5186-1 Critical: Firefox DoS and Code Execution Threat

ubuntu

December 9, 2021

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

Summary

Firefox could be made to crash or run programs as your login if it

opened a malicious website.

Software Description:

- firefox: Mozilla Open Source web browser

Details:

Multiple security issues were discovered in Firefox. If a user were

tricked into opening a specially crafted website, an attacker could

potentially exploit these to cause a denial of service, obtain sensitive

information, conduct spoofing attacks, bypass CSP restrictions, or

execute arbitrary code. (CVE-2021-43536, CVE-2021-43537, CVE-2021-43538,

CVE-2021-43539, CVE-2021-43541, CVE-2021-43542, CVE-2021-43543,

CVE-2021-43545, CVE-2021-43546)

A security issue was discovered with the handling of WebExtension

permissions. If a user were tricked into installing a specially crafted

extension, an attacker could potentially exploit this to create and

install a service worker that wouldn't be uninstalled with the extension.

(CVE-2021-43540)

Topics Covered

security advisory denial of service arbitrary code execution critical update firefox ubuntu

Update Instructions

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

Ubuntu 21.10:
  firefox                         95.0+build1-0ubuntu0.21.10.1

Ubuntu 21.04:
  firefox                         95.0+build1-0ubuntu0.21.04.1

Ubuntu 20.04 LTS:
  firefox                         95.0+build1-0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
  firefox                         95.0+build1-0ubuntu0.18.04.1

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