Stack-based buffer overflow in the mozilla::FileBlockCache::Read function in Mozilla Firefox before 34.0, Firefox ESR 31.x before 31.3, Thunderbird before 31.3, and SeaMonkey before 2.31 allows remote attackers to execute arbitrary code via crafted media content.
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.