Dental Clinic Appointment Reservation System 1.0 - 'Firstname' Persistent Cross Site Scripting (Authenticated)

# Exploit Title: Dental Clinic Appointment Reservation System 1.0 - 'Firstname' Persistent Cross Site Scripting (Authenticated)
# Date: 14-05-2021
# Exploit Author: Reza Afsahi
# Vendor Homepage: https://www.sourcecodester.com/php/6848/appointment-reservation-system.html
# Software Link: https://www.sourcecodester.com/download-code?nid=6848&title=Dental+Clinic+Appointment+Reservation+System+in+PHP+with+Source+Code
# Version: 1.0
# Tested on: Linux parrot

# --- Description --- #

# The web application allows member to inject persistent Cross-Site-Scripting payload which will be executed in both member and Admin panel  

# --- Proof of concept --- #

1- Create account and login as member and go to:  http://localhost/APR/edit_info.php
2- Inject this payload into Firstname input : <script>alert(document.cookie)</script>
4- and fill other inputs as you want (Other inputs might be vulnerable as well) then click on Update button.
5- refresh the page and Xss popup will be triggered.

6- Now if Admin visit this page in his/her Dashboard : http://localhost/APR/admin/members.php
7- Our Xss payload will be executed on Admin Browser

** Attacker can use this vulnerability to take over Admin account **