Mozilla Foundation Security Advisory 2015-107

Out-of-bounds read during 2D canvas display on Linux 16-bit color depth systems

Announced
September 22, 2015
Reporter
Francisco Alonso
Impact
Moderate
Products
Firefox, SeaMonkey
Fixed in
  • Firefox 41
  • SeaMonkey 2.38

Description

Security researcher Francisco Alonso of the NowSecure Research Team used the Address Sanitizer tool to discover an out-of-bounds read issue during 2D canvas rendering. This was due to an issue in the cairo graphics library when surfaces are created with 32-bit color depth but displayed on a 16-bit color depth system, which is unsupported. This allows an attacker to read an amount of random memory following the heap for the 16-bit surface leading to information disclosure.

This issue is specific to Linux in certain configurations and does not affect Windows or OS X systems.

References