writeRandomBytes_arc4random(void * target, size_t count) {
  size_t bytesWrittenTotal = 0;

  while (bytesWrittenTotal < count) {
    const uint32_t random32 = arc4random();
    size_t i = 0;

    for (; (i < sizeof(random32)) && (bytesWrittenTotal < count);
        i++, bytesWrittenTotal++) {
      const uint8_t random8 = (uint8_t)(random32 >> (i * 8));
      ((uint8_t *)target)[bytesWrittenTotal] = random8;
    }
  }
}

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.