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]