Smart Slider 3 <= 3.5.1.33 - Missing Authorization to Authenticated (Contributor+) Slider Data Read and Image Record Manipulation

The Smart Slider 3 plugin for WordPress is vulnerable to unauthorized access and modification of data due to missing capability checks on multiple wp_ajax_smart-slider3 controller actions in all versions up to, and including, 3.5.1.33. The display_admin_ajax() method does not call checkForCap() (which requires unfiltered_html capability), and several controller actions only validate the nonce (validateToken()) without calling validatePermission(). This makes it possible for authenticated attackers, with Contributor-level access and above, to enumerate slider metadata and create, modify, and delete image storage records by obtaining the nextend_nonce exposed on post editor pages.