Bento4 1.6.0.0 contains an integer underflow vulnerability in the avcC and hvcC configuration atom parsers. A specially crafted MP4 file containing an atom with a declared size smaller than AP4_ATOM_HEADER_SIZE can cause AP4_AvccAtom::Create() or AP4_HvccAtom::Create() to underflow the payload-size calculation. The resulting oversized buffer operation can cause invalid or NULL pointers to be passed to the AP4_DataBuffer copy path, resulting in application termination and denial of service.