=========================================================================Ubuntu Security Notice USN-2768-1
October 16, 2015

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

- Ubuntu 15.04
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS

Summary:

Firefox could be made to expose sensitive information across origins

Software Description:
- firefox: Mozilla Open Source web browser

Details:

Abdulrahman Alqabandi and Ben Kelly discovered that the fetch() API did
not correctly implement the Cross Origin Resource Sharing (CORS)
specification. If a user were tricked in to opening a specially crafted
website, an attacker could potentially exploit this to obtain sensitive
information from other origins. (CVE-2015-7184)

Update instructions:

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

Ubuntu 15.04:
  firefox                         41.0.2+build2-0ubuntu0.15.04.1

Ubuntu 14.04 LTS:
  firefox                         41.0.2+build2-0ubuntu0.14.04.1

Ubuntu 12.04 LTS:
  firefox                         41.0.2+build2-0ubuntu0.12.04.1

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

References:
  
  CVE-2015-7184

Package Information:
  https://launchpad.net/ubuntu/+source/firefox/41.0.2+build2-0ubuntu0.15.04.1
  https://launchpad.net/ubuntu/+source/firefox/41.0.2+build2-0ubuntu0.14.04.1
  https://launchpad.net/ubuntu/+source/firefox/41.0.2+build2-0ubuntu0.12.04.1