An issue was discovered in SourceCodester Seat Reservation System 1.0. The file admin_class.php does not perform input validation on the username and password parameters. An attacker can send malicious input in the post request to /admin/ajax.php?action=login and bypass authentication, extract sensitive information etc.
https://packetstormsecurity.com/files/author/15149
http://seclists.org/fulldisclosure/2020/Sep/42
http://packetstormsecurity.com/files/159261/Seat-Reservation-System-1.0-SQL-Injection.html