codecs/amrnb/dec/SoftAMR.cpp in libstagefright in mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-05-01 does not validate buffer sizes, which allows attackers to gain privileges via a crafted application, as demonstrated by obtaining Signature or SignatureOrSystem access, aka internal bugs 27662364 and 27843673.
https://android.googlesource.com/platform/frameworks/av/+/daa85dac2055b22dabbb3b4e537597e6ab73a866
https://android.googlesource.com/platform/frameworks/av/+/65756b4082cd79a2d99b2ccb5b392291fd53703f
https://android.googlesource.com/platform/frameworks/av/+/44749eb4f273f0eb681d0fa013e3beef754fa687