long UnserializeString(IMkvReader* pReader, long long pos, long long size,
 char*& str) {
 delete[] str;
  str = NULL;

 if (size >= LONG_MAX || size < 0)
 return E_FILE_FORMAT_INVALID;

 const long required_size = static_cast<long>(size) + 1;

  str = SafeArrayAlloc<char>(1, required_size);
 if (str == NULL)
 return E_FILE_FORMAT_INVALID;

 unsigned char* const buf = reinterpret_cast<unsigned char*>(str);

 const long status = pReader->Read(pos, size, buf);

 if (status) {
 delete[] str;
    str = NULL;

 return status;
 }

  str[required_size - 1] = '\0';
 return 0;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.