Tencent RapidJSON include/rapidjson/reader.h GenericReader::ParseNumber() Function Template Exponent Parsing Integer Underflow

Tencent RapidJSON is vulnerable to privilege escalation due to an integer underflow in the `GenericReader::ParseNumber()` function of `include/rapidjson/reader.h` when parsing JSON text from a stream. An attacker needs to send the victim a crafted file which needs to be opened; this triggers the integer underflow vulnerability (when the file is parsed), leading to elevation of privilege.