Heap-based buffer overflow in the mozilla::gfx::CopyRect function in Mozilla Firefox before 36.0, Firefox ESR 31.x before 31.5, and Thunderbird before 31.5 allows remote attackers to obtain sensitive information from uninitialized process memory via a malformed SVG graphic.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.