Broadstreet <= 1.52.2 - Authenticated (Subscriber+) Private Post Meta Disclosure via get_sponsored_meta

The Broadstreet plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.52.2 via the get_sponsored_meta AJAX action due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Subscriber-level access and above, to disclose any private post metadata.