The (1) av_image_fill_pointers, (2) vp5_parse_coeff, and (3) vp6_parse_coeff functions in FFmpeg 0.5.x before 0.5.7, 0.6.x before 0.6.4, 0.7.x before 0.7.9, and 0.8.x before 0.8.8; and in Libav 0.5.x before 0.5.6, 0.6.x before 0.6.4, and 0.7.x before 0.7.3 allow remote attackers to cause a denial of service (out-of-bounds read) via a crafted VP5 or VP6 stream.
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.