The Gallery Metabox for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the refresh_metabox function in versions up to, and including, 1.5. This makes it possible for subscriber-level attackers to obtain a list of images attached to a post.
https://plugins.trac.wordpress.org/browser/gallery-metabox/trunk/gallery-metabox.php?rev=611664#L203