The WP Shortcodes Plugin — Shortcodes Ultimate plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.13.3 via the su_meta shortcode due to missing validation on the user controlled keys 'key' and 'post_id'. This makes it possible for authenticated attackers, with contributor-level access and above, to retrieve arbitrary post meta values which may contain sensitive information when combined with another plugin.
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.