USN-3111-1: Firefox vulnerabilities

27 October 2016

firefox vulnerabilities

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

  • Ubuntu 16.10
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS


Several security issues were fixed in Firefox.

Software Description

  • firefox - Mozilla Open Source web browser


A use-after-free was discovered in service workers. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit this to cause a denial of service via program crash, or execute arbitrary code. (CVE-2016-5287)

It was discovered that web content could access information in the HTTP cache in some circumstances. An attacker could potentially exploit this to obtain sensitive information. (CVE-2016-5288)

Update instructions

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

Ubuntu 16.10
firefox - 49.0.2+build2-0ubuntu0.16.10.2
Ubuntu 16.04 LTS
firefox - 49.0.2+build2-0ubuntu0.16.04.2
Ubuntu 14.04 LTS
firefox - 49.0.2+build2-0ubuntu0.14.04.1
Ubuntu 12.04 LTS
firefox - 49.0.2+build2-0ubuntu0.12.04.1

To update your system, please follow these instructions:

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