The ff_sbr_apply function in libavcodec/aacsbr.c in FFmpeg before 2.7.2 does not check for a matching AAC frame syntax element before proceeding with Spectral Band Replication calculations, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted AAC data.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.