sp5xdec.c in the Sunplus SP5X JPEG decoder in libavcodec in FFmpeg before 0.6.3 and libav through 0.6.2, as used in VideoLAN VLC media player 1.1.9 and earlier and other products, performs a write operation outside the bounds of an unspecified array, which allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via a malformed AMV file.