Discount Rules for WooCommerce < 2.1.0 - Multiple Vulnerabilities

Description

The Discount Rules for WooCommerce plugin (versions below 2.1.0) suffers from multiple vulnerabilities such as SQL injection, authorization issues and unauthenticated stored cross-site scripting.

The issues in this plugin are caused due to a lack of authorization and nonce token check. The plugin registers several AJAX actions of which one, wp_ajax_wdr_ajax, handles a bulk of different AJAX actions which are supposedly only be accessed by administrators.

Unfortunately this AJAX action is also registered as wp_ajax_nopriv_wdr_ajax. Even if wp_ajax_nopriv_wdr_ajax was not registered, authenticated users could still exploit this since wp_ajax_wdr_ajax does not perform any type of authorization or CSRF check.

Particularly the wdr_ajax_save_configuration method that can be executed in this AJAX action can cause significant damage to the site as it allows you to write any type of HTML or JavaScript to any template hook of the site, including wp-admin.