The adpcm_decode_frame function in adpcm.c in libavcodec in FFmpeg before 0.9.1 and in Libav 0.5.x before 0.5.9, 0.6.x before 0.6.6, 0.7.x before 0.7.6, and 0.8.x before 0.8.3 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via an ADPCM file with the number of channels not equal to two.