Askeet <= 3.0 - Authenticated (Administrator+) SQL Injection via 'sql_query' Parameter

Summary

The Askeet plugin for WordPress is vulnerable to SQL Injection via the 'sql_query' parameter in multiple AJAX actions (askeet_execute_sql_query, askeet_export_all_results) in all versions up to, and including, 3.0. This is due to the askeet_is_safe_query() filter being bypassable using MySQL conditional comments (e.g., /*!UNION*/). The filter strips regular block comments before checking for forbidden SQL keywords, but MySQL interprets conditional comments as executable code. This makes it possible for authenticated attackers, with Administrator-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.