Art Theme <= 3.12.2.3 - Missing Authorization to Authenticated (Subscriber+) Theme Option Delete

The Art Theme for WordPress is vulnerable to unauthorized access due to a missing capability check on the 'arttheme_theme_option_restore' AJAX function in all versions up to, and including, 3.12.2.3. This makes it possible for authenticated attackers, with subscriber-level access and above, to delete the theme option.