The Product Filtering by Categories, Tags, Price Range for WooCommerce – Filter Plus plugin for WordPress is vulnerable to unauthorized modification of data in all versions up to, and including, 1.1.6 due to a missing capability check on the 'filter_save_settings' and 'add_filter_options' AJAX actions. This makes it possible for unauthenticated attackers to modify the plugin's settings and create arbitrary filter options.
https://plugins.trac.wordpress.org/browser/filter-plus/tags/1.1.7/core/admin/settings/action.php#L23
https://plugins.trac.wordpress.org/browser/filter-plus/tags/1.1.5/core/admin/settings/action.php#L82
https://plugins.trac.wordpress.org/browser/filter-plus/tags/1.1.5/core/admin/settings/action.php#L28
https://plugins.trac.wordpress.org/browser/filter-plus/tags/1.1.5/core/admin/settings/action.php#L23
https://plugins.trac.wordpress.org/browser/filter-plus/tags/1.1.5/base/enqueue.php#L178