function invalidTestController($port) {
  $host = 'localhost';

  $filename = __DIR__.'/request-doesnotexist.dat';
  $file = fopen($filename, 'rb');
  $req_dat = fread($file, filesize($filename));
  fclose($file);

  // Repeat the data three times, to make it invalid. This particular bytestream
  // (and ones like it -- repeat 3 times!) in particular used to tickle a
  // use-after-free in the FastCGI support.
  $req_dat = $req_dat . $req_dat . $req_dat;

  $sock = fsockopen($host, $port);
  fwrite($sock, $req_dat);
  fclose($sock);

  // Should still be able to recover and respond to a request over the port on a
  // new TCP connection.
  echo request($host, $port, 'hello.php');
  echo "\n";
}
The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.