Tutor LMS < 2.2.0 - Unauthenticate SQL Injection

Description

The plugin is vulnerable to SQL Injection via many parameters in versions up to, and including, 2.1.10 due to insufficient escaping on the user supplied parameters and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.