CubeWP Framework < 1.1.31 - Authenticated (Subscriber+) SQL Injection via 'relation_id' Parameter

Description

The CubeWP Framework plugin for WordPress is vulnerable to SQL Injection in all versions up to and including 1.1.30. This is due to insufficient input sanitization in the cubewp_remove_relation() AJAX function, specifically the use of wp_unslash() on the relation_id parameter before interpolating it directly into a raw SQL query without using $wpdb->prepare(). The wp_unslash() call explicitly removes the backslash escaping that WordPress's wp_magic_quotes() adds to all $_POST data, neutralizing the only layer of SQL injection protection. The sanitize_text_field() function applied afterward offers no SQL protection. This makes it possible for authenticated attackers, with subscriber-level access and above, to append additional SQL queries to the existing query.