CoreGraphics in Apple iOS before 8 and Apple TV before 7 allows remote attackers to obtain sensitive information or cause a denial of service (out-of-bounds read and application crash) via a crafted PDF document.
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.