Google V8, as used in Google Chrome before 38.0.2125.101, does not properly track JavaScript heap-memory allocations as allocations of uninitialized memory and does not properly concatenate arrays of double-precision floating-point numbers, which allows remote attackers to obtain sensitive information via crafted JavaScript code, related to the PagedSpace::AllocateRaw and NewSpace::AllocateRaw functions in heap/spaces-inl.h, the LargeObjectSpace::AllocateRaw function in heap/spaces.cc, and the Runtime_ArrayConcat function in runtime.cc.