Client Management System 1.1 - 'username' Stored Cross-Site Scripting (XSS)

# Exploit Title: Client Management System 1.1 - 'username' Stored Cross-Site Scripting (XSS)
# Date: 14 June 2021
# Exploit Author: BHAVESH KAUL
# Vendor Homepage: https://phpgurukul.com
# Software Link: https://phpgurukul.com/client-management-system-using-php-mysql/
# Version: 1.1
# Tested on: Server: XAMPP

# Description #

Client Management System 1.1 is vulnerable to stored cross site scripting because of insufficient user supplied data sanitization. 

# Proof of Concept (PoC) : Exploit #

1) Goto: http://localhost/clientms/admin/index.php
2) Login as admin using test credentials: admin/Test@123
3) Goto: http://localhost/clientms/admin/admin-profile.php
4) Enter the following payload in the user name field: <script>alert(1)</script>
5) Click on Update
6) Our payload is fired and stored