WordPress AudioIgniter <= 2.0.2 - Unauthenticated IDOR

The AudioIgniter plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to, and including, 2.0.2. This is due to the handle_playlist_endpoint() function (hooked to template_redirect) accepting a user-controlled playlist ID via the audioigniter_playlist_id query var or the /audioigniter/playlist/{id}/ rewrite rule and returning playlist track data without performing any authentication, capability, or post_status check — only the post_type is validated. This makes it possible for unauthenticated attackers to view track metadata (titles, artists, audio URLs, buy links, download URLs, and cover images) of any playlist on the site, including those in draft, private, pending, or trash status.