Tickera <= 3.6.0.1 - Authenticated (Staff+) SQL Injection via 'tc_event_filter' Parameter

The Tickera – Sell Tickets & Manage Events plugin for WordPress is vulnerable to generic SQL Injection via the 'tc_event_filter' parameter in all versions up to, and including, 3.6.0.1 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with staff-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. The vulnerable code path is reachable by users holding the plugin's custom Staff role, as the plugin's add_required_capabilities() function grants that role the edit_tc_tickets_instances capability, providing access to the tc_tickets_instances admin list screen where the filter is applied.