The Photo Gallery Slideshow & Masonry Tiled Gallery plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.0.15 via the rjg_get_youtube_info_justified_gallery_callback function. This makes it possible for authenticated attackers, with Subscriber-level access and above, to make web requests to arbitrary locations originating from the web application and can be used to retrieve limited information from internal services.