The MPEG4Extractor::parse3GPPMetaData function in MPEG4Extractor.cpp in libstagefright in Android before 5.1.1 LMY48I does not enforce a minimum size for UTF-16 strings containing a Byte Order Mark (BOM), which allows remote attackers to execute arbitrary code or cause a denial of service (integer underflow and memory corruption) via crafted 3GPP metadata, aka internal bug 20923261, a related issue to CVE-2015-3826.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.