SecurityReason - Critical SQL Injection PHPNuke <= 7.8 - Your

Advisory Text :

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SecurityAlert SA032

Author: sp3x
CVE : CVE-2006-0679
Date: 16. February 2006

Affected software :
===================

PHPNuke version : 7.8 with all security fixes/patches

Not Affected software :
=======================

PHPNuke version : 7.9 + patch 3.1

Description :
=============
PHP-Nuke is a Web Portal System, storytelling software, News system, online
community or whatever you want to call it. The goal of PHP-Nuke is to have
an automated web site to distribute news and articles with users system.
Each user can submit comments to discuss the articles, just similar to
Slashdot and many others. Main features include: web based admin, surveys,
top page, access stats page with counter, user customizable box, themes
manager for registered users, friendly administration GUI with graphic
topic manager, option to edit or delete stories, option to delete comments,
moderation system, Referers page to know who link us, sections manager,
customizable HTML blocks, user and authors edit, an integrated Banners Ads
system, search engine, backend/headlines generation (RSS/RDF format), and
many, many more friendly functions. PHP-Nuke is written 100% in PHP and
requires Apache Web server, PHP and a SQL (MySQL, mSQL, PostgreSQL, ODBC,
ODBC_Adabas, Sybase or Interbase). Support for 25 languages, Yahoo like
search engine, Comments option in Polls, lot of themes, Ephemerids manager,
File Manager, Headlines, download manager, faq manager, advanced blocks
systems, reviews system, newsletter, categorized articles, multilanguage
content management, phpBB Forums included and a lot more.

Vulnerabilities :
*****************

Critical SQL injection :
==========================

IN module called "Your_Account" there exists SQL Injection bug, which can
lead to stealing admin`s username and password md5 and also some sensitive
data from database.

The problem exist in index.php so first let's see the source code of this
file.

Original code from index.php :
- ---------------------------------
...
function confirmNewUser($username, $user_email, $user_password,
$user_password2, $random_num, $gfx_check) {
global $stop, $EditedMessage, $sitename, $module_name, $minpass;
include("header.php");
include("config.php");
filter_text($username);
$username = $EditedMessage;
$user_viewemail = "0";
userCheck($username, $user_email);
$user_email = validate_mail($user_email);
....
- -----------------------------------

Here we can see that there is filter_text() used on $query variable and
later we have userCheck($username, $user_email); ,
Ok lets see function filter_text(); .
Orginal code from mainfile.php :
- ----------------------------------
function filter_text($Message, $strip="") {
global $EditedMessage;
check_words($Message);
$EditedMessage=check_html($EditedMessage, $strip);
return $EditedMessage;
}
- -----------------------------------
Here we have another function check_words($Message); , lets check this also
:

Orginal code from mainfile.php :
- --------------------------------
function check_html ($str, $strip="") {
/* The core of this code has been lifted from phpslash */
/* which is licenced under the GPL. */
include("config.php");
if ($strip == "nohtml")
global $AllowableHTML;
if (!is_array($AllowableHTML)) $AllowableHTML =array('');
$str = stripslashes($str);
$str = eregi_replace("<[[:space:]]*([^>]*)[[:space:]]*>",'<\\1>', $str);
// Delete all spaces from html tags .
$str =
eregi_replace("<a[^>]*href[[:space:]]*=[[:space:]]*\"?[[:space:]]*([^\"
>]*)[[:space:]]*\"?[^>]*>",'<a href="\\1">', $str);
// Delete all attribs from Anchor, except an href, double quoted.
$str = eregi_replace("<[[:space:]]* img[[:space:]]*([^>]*)[[:space:]]*>",
'', $str);
// Delete all img tags
$str =
eregi_replace("<a[^>]*href[[:space:]]*=[[:space:]]*\"?javascript[[:punct:]]
*\"?[^>]*>", '', $str);
// Delete javascript code from a href tags -- Zhen-Xjell @
http://nukecops.com
$tmp = "";
while (ereg("<(/?[[:alpha:]]*)[[:space:]]*([^>]*)>",$str,$reg)) {
$i = strpos($str,$reg[0]);
$l = strlen($reg[0]);
if ($reg[1][0] == "/") $tag = strtolower(substr($reg[1],1));
else $tag = strtolower($reg[1]);
if ($a = $AllowableHTML[$tag])
if ($reg[1][0] == "/") $tag = "</$tag>";
elseif (($a == 1) || (empty($reg[2]))) $tag = "<$tag>";
else {
# Place here the double quote fix function.
$attrb_list=delQuotes($reg[2]);
// A VER
$attrb_list = str_replace("&","&",$attrb_list);
$tag = "<$tag" . $attrb_list . ">";
} # Attribs in tag allowed
else $tag = "";
$tmp .= substr($str,0,$i) . $tag;
$str = substr($str,$i+$l);
}
$str = $tmp . $str;
return $str;
exit;
/* Squash PHP tags unconditionally */
$str = str_replace("<?","",$str);
return $str;
}
- ----------------------------------------
This function return $str variable but at the beginning of this function we
can see
$str = stripslashes($str); .
So when we have in index.php :
filter_text($username);
this mean that on variable $username is used stripslashes();
Lower in index.php we can see :
userCheck($username, $user_email);
So another function userCheck(); that uses $username variable , lets see
the code :

Orginal code from index.php :
- -----------------------------
....
function userCheck($username, $user_email) {
global $stop, $user_prefix, $db;
if ((!$user_email) || (empty($user_email)) ||
(!eregi("^[_\.0-9a-z-]+@([0-9a-z][0-9a-z-]+\.)+[a-z]{2,6}$",$user_email)))
$stop = "<center>"._ERRORINVEMAIL."</center><br>";
if (strrpos($user_email,' ') > 0) $stop =
"<center>"._ERROREMAILSPACES."</center>";
if ((!$username) || (empty($username)) ||
(ereg("[^a-zA-Z0-9_-]",$username))) $stop =
"<center>"._ERRORINVNICK."</center><br>";
if (strlen($username) > 25) $stop = "<center>"._NICK2LONG."</center>";
if
(eregi("^((root)|(adm)|(linux)|(webmaster)|(admin)|(god)|(administrator)|(a
dministrador)|(nobody)|(anonymous)|(anonimo)|(anónimo)|(operator)|(JackFrom
Wales4u2))$",$username)) $stop = "<center>"._NAMERESERVED."</center>";
if (strrpos($username,' ') > 0) $stop =
"<center>"._NICKNOSPACES."</center>";
if ($db->sql_numrows($db->sql_query("SELECT username FROM
".$user_prefix."_users WHERE username='$username'")) > 0) $stop =
"<center>"._NICKTAKEN."</center><br>";
if ($db->sql_numrows($db->sql_query("SELECT username FROM
".$user_prefix."_users_temp WHERE username='$username'")) > 0) $stop =
"<center>"._NICKTAKEN."</center><br>";
.......
- --------------------------------
In this function we see two sql queries :
SELECT username FROM ".$user_prefix."_users WHERE username='$username'
SELECT username FROM ".$user_prefix."_users_temp WHERE
username='$username'

At last here now we can say : "Critical SQL injection "

Time to exploit this issue :
Go to :
http://[victim]/[phpnuke_dir]/modules.php?name=Your_Account&op=new_user
And fill in all Fields but in Nickname: field enter : ' or 1=1/*
The Result is :
- --------------
ERROR: Nickname already taken
- --------------
So the SQl injection is working but we can't see the results ...
It doesn't metter we can all our results write to file .

To do this i wrote a little exploit .

Exploit :
- ---------

http://securityreason.com/achievement_exploitalert/7

How to fix :
============

Download the new version of the script or update.

Greets :
========

Special greets : cXIb8O3

And the rest : pkw , p_e_a, pi3, LordDav and alkeniu

Contact :
=========

sp3x[at]securityreason[dot]com
GPG: http://securityreason.com/key/sp3x.gpg
www.securityreason.com
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