WOOF WooCommerce Products Filter 1.1.9 LFI / Code Execution

`SEC Consult Vulnerability Lab Security Advisory < 20180314-0 >  
=======================================================================  
title: Arbitrary Shortcode Execution & Local File Inclusion  
product: WOOF - WooCommerce Products Filter (PluginUs.Net)  
vulnerable version: 1.1.9  
fixed version: 2.2.0  
CVE number: (requested but not yet received)  
impact: Critical  
homepage: https://pluginus.net/  
found: 2018-02-20  
by: Ahmad Ramadhan Amizudin (Office Kuala Lumpur)  
SEC Consult Vulnerability Lab  
  
An integrated part of SEC Consult  
Europe | Asia | North America  
  
https://www.sec-consult.com  
  
=======================================================================  
  
Vendor description:  
-------------------  
"PluginUs.Net is a little team of talented professionals from Ukraine. Unlike  
most of the big companies on the net, we believe in individual approach to  
every our customer. Web development is our passion and we always try to go an  
extra mile over our clients' expectations.  
  
Our team specializes in development of WordPress plugins. It's always exciting  
to try new technologies and approaches to get the project done and impress  
clients by realization of their ideas!"  
  
Source: https://pluginus.net/about-us/  
  
  
Business recommendation:  
------------------------  
SEC Consult recommends to ugprade to the latest version available  
as soon as possible. Further detailed security tests should be performed  
in order to identify potential other security issues.  
  
  
Vulnerability overview/description:  
-----------------------------------  
1. Arbitrary Shortcode Execution  
The plugin implemented a page redraw AJAX function accessible to anyone  
without any authentication.  
  
WordPress shortcode markup in the "shortcode" parameters would be evaluated.  
Normally unauthenticated users can't evaluate shortcodes as they are often  
sensitive.  
  
Additionally, it is noted that there are other implemented shortcodes that are  
being used in this plugin which can be abused through the same attack. Worst,  
some of them could lead to remote code execution.  
  
  
2. Local File Inclusion  
The vulnerability is due to the lack of args/input validation on render_html  
before allowing it to be called by extract(), a PHP built-in function. Because  
of this, the supplied args/input can be used to overwrite the $pagepath  
variable which then could lead to local file inclusion attack.  
  
  
Proof of concept:  
-----------------  
1. Arbitrary Shortcode Execution  
The parameter "shortcode" within the "admin-ajax.php" script is affected by  
the code execution vulnerability:  
  
POST /wp-admin/admin-ajax.php HTTP/1.1  
[...]  
  
action=woof_redraw_woof&shortcode=<<shortcode without []>>  
  
  
2. Local File Inclusion  
The parameter "shortcode" within the "admin-ajax.php" script is affected by  
the local file inclusion vulnerability:  
  
POST /wp-admin/admin-ajax.php HTTP/1.1  
[...]  
  
action=woof_redraw_woof&shortcode=woof_search_options pagepath=/etc/passwd  
  
  
Vulnerable / tested versions:  
-----------------------------  
PluginUs.Net WooCommerce Products Filter version 1.1.9 has been tested and  
found to be vulnerable.  
  
  
Vendor contact timeline:  
------------------------  
2018-02-20: Contacting vendor through [email protected]  
2018-02-20: Vendor agreed to proceed without encrypted channel  
2018-02-21: Sent security advisory to vendor  
2018-02-26: Vendor sent patch containing the fixes  
2018-02-26: Informed vendor the patch doesn't fully mitigate the vulnerability  
2018-03-12: Request update from vendor  
2018-03-12: Vendor said they already published the patch  
2018-03-14: Public release of security advisory  
  
  
Solution:  
---------  
The vendor provides an updated version and users are urged to upgrade to version  
2.2.0 immediately:  
  
https://www.woocommerce-filter.com/update-woocommerce-products-filter-v-2-2-0/  
  
  
Workaround:  
-----------  
None  
  
  
Advisory URL:  
-------------  
https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html  
  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
SEC Consult Vulnerability Lab  
  
SEC Consult  
Europe | Asia | North America  
  
About SEC Consult Vulnerability Lab  
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EOF Ahmad Ramadhan / @2018  
  
`