USN-4299-1: Firefox vulnerabilities

11 March 2020

firefox vulnerabilities

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

  • Ubuntu 19.10
  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS


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


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, spoof the URL or other browser chrome, obtain sensitive information, bypass Content Security Policy (CSP) protections, or execute arbitrary code. (CVE-2019-20503, CVE-2020-6805, CVE-2020-6806, CVE-2020-6807, CVE-2020-6808, CVE-2020-6810, CVE-2020-6812, CVE-2020-6813, CVE-2020-6814, CVE-2020-6815)

It was discovered that Web Extensions with the all-url permission could access local files. If a user were tricked in to installing a specially crafted extension, an attacker could potentially exploit this to obtain sensitive information. (CVE-2020-6809)

It was discovered that the Devtools’ ‘Copy as cURL’ feature did not fully escape website-controlled data. 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 execute arbitrary commands via command injection. (CVE-2020-6811)

Update instructions

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

Ubuntu 19.10
firefox - 74.0+build3-0ubuntu0.19.10.1
Ubuntu 18.04 LTS
firefox - 74.0+build3-0ubuntu0.18.04.1
Ubuntu 16.04 LTS
firefox - 74.0+build3-0ubuntu0.16.04.1

To update your system, please follow these instructions:

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