Heap-based buffer overflow in the MPV_frame_start function in libavcodec/mpegvideo.c in FFmpeg before 0.9.1, when the lowres option is enabled, allows remote attackers to cause a denial of service (application crash) via a crafted H263 media file. NOTE: this vulnerability exists because of a regression error.
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.