ACF Photo Gallery Field <= 1.9 - Authenticated (Subscriber+) Arbitrary Usermeta Update

The ACF Photo Gallery Field plugin for WordPress is vulnerable to unauthorized modification of data due to an insufficient restriction on the 'apg_profile_update' function in versions up to, and including, 1.9. This makes it possible for authenticated attackers, with subscriber-level permissions or above, to update the user metas arbitrarily. The meta value can only be a string.