rtMedia for WordPress, BuddyPress and bbPress <= 4.7.11 - Unauthenticated SQL Injection via 'compare' Parameter

The rtMedia for WordPress, BuddyPress and bbPress plugin for WordPress is vulnerable to time-based blind SQL Injection via the 'compare' parameter in all versions up to, and including, 4.7.11 due to insufficient escaping on the user supplied parameter 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. This is exploitable on any public page containing an rtMedia shortcode (e.g., [rtmedia_gallery]) when the rtmedia_shortcode GET parameter is set, because RTMediaQuery::query() merges $_REQUEST into the internal query while only validating top-level array keys, allowing the nested 'compare' subvalue to reach the vulnerable sink without authentication.