The QCMS implementation in Mozilla Firefox before 37.0 allows remote attackers to obtain sensitive information from process heap memory or cause a denial of service (out-of-bounds read) via an image that is improperly handled during transformation.
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.