The allocate_buffers function in libavcodec/alac.c in FFmpeg before 2.7.2 does not initialize certain context data, which allows remote attackers to cause a denial of service (segmentation violation) or possibly have unspecified other impact via crafted Apple Lossless Audio Codec (ALAC) data. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-6823