Jcow CMS 4.x:4.2 <= , 5.x:5.2 <= | Arbitrary Code Execution

Jcow CMS 4.x:4.2 <= , 5.x:5.2 <= | Arbitrary Code Execution

1. OVERVIEW

Jcow CMS versions (4.x: 4.2 and lower, 5.x: 5.2 and lower) are
vulnerable to Arbitrary Code Execution.

2. BACKGROUND

Jcow is a flexible Social Networking software written in PHP. It can
help you to build a social network for your interests and passions, a
member community for your existing website and a social networking
site like facebook/myspace/twitter.

3. VULNERABILITY DESCRIPTION

The parameter "attachment" is not properly sanitized upon submission
to /index.php, which allows attacker to execute arbitrary PHP code of
his own.

4. VERSIONS AFFECTED

Free version: 4.x: 4.2 and lower
Commercial version: 5.x: 5.2 and lower

5. PROOF-OF-CONCEPT/EXPLOIT

http://dev.metasploit.com/redmine/attachments/1660/jcow_eval.rb

jcow 4.2.1:
file: /includes/libs/ss.inc.php
line: 167

    $app = $_POST['attachment'];
if (strlen($app) && $app != 'status') {
    include_once('modules/'.$app.'/'.$app.'.php');
    $c_run = $app.'::ajax_post();';
    eval($c_run);
    exit;
}

jcow 5.2.0:
file: /includes/libs/ss.inc.php
line: 45

$Vd2a57dc1 = $_POST['attachment']; if (strlen($Vd2a57dc1) &&
$Vd2a57dc1 != 'status') {
include_once('modules/'.$Vd2a57dc1.'/'.$Vd2a57dc1.'.php'); $Ve8200cee
= $Vd2a57dc1.'::ajax_post();';
eval($Ve8200cee); exit; }

6. SOLUTION

Free version users can upgrade to 4.3.1 or higher.
Commercial users can upgrade to 5.3 or higher.

7. VENDOR

Jcow CMS Development Team
http://www.jcow.net

8. CREDIT

This vulnerability was discovered by Aung Khant, http://yehg.net, YGN
Ethical Hacker Group, Myanmar.

9. DISCLOSURE TIME-LINE

2010-06-03: notified vendor
2010-06-03: vendor replied fix would be available within 48hrs
2011-08-24: vendor released fixed versions for 4.x and 5.x,
4.3.1 for free release
5.3 for commercial release
2011-08-26: vulnerability disclosed

10. REFERENCES

Original Advisory URL:
http://yehg.net/lab/pr0js/advisories/[jcow_4.2,5.2]_arbitrary_code_execution
Jcow CMS: http://sourceforge.net/projects/jcow/files/jcow4/jcow.4.2.1.zip/download

#yehg [2011-08-26]

---

Best regards,
YGN Ethical Hacker Group
Yangon, Myanmar
http://yehg.net
Our Lab | http://yehg.net/lab
Our Directory | http://yehg.net/hwd