Quick Featured Images <= 13.7.0 - Missing Authorization to Authenticated (Contributor+) Arbitrary Thumbnail Deletion/Setting

The Quick Featured Images plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the set_thumbnail and delete_thumbnail functions in all versions up to, and including, 13.7.0. This makes it possible for authenticated attackers, with contributor-level access and above, to delete thumbnails and add thumbnails to posts they did not author.