Slim SEO <= 4.11.1 - Authenticated (Subscriber+) Arbitrary Shortcode Execution via 'Biographical Info' User Meta

The The Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 4.11.1 This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for authenticated attackers, with subscriber-level access and above, to execute arbitrary shortcodes. A Subscriber-level user need only save the shortcode payload to their own Biographical Info field via the REST API or wp-admin profile page; the shortcode then executes on any unauthenticated front-end request that resolves that author's description, such as requests using the ?author= query parameter when auto_redirection is disabled.