Buffer overflow in the Sierra VMD decoder in libavcodec 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 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted VMD file, related to corrupted streams.