The Display custom fields in the frontend – Post and User Profile Fields plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.2.1 via the vg_display_data shortcode due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with contributor-level access and above, to retrieve potentially sensitive post meta.
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.