The get_siz function in libavcodec/jpeg2000dec.c in FFmpeg before 2.1 does not ensure the expected sample separation, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted JPEG2000 data.
http://openwall.com/lists/oss-security/2013/11/26/7
http://openwall.com/lists/oss-security/2013/12/08/3
https://github.com/FFmpeg/FFmpeg/commit/8bb11c3ca77b52e05a9ed1496a65f8a76e6e2d8f