Responsive Plus < 3.4.3 - Unauthenticated Arbitrary Shortcode Execution

The Responsive Plus WordPress plugin before 3.4.3 is vulnerable to arbitrary shortcode execution due to the software allowing unauthenticated users to execute the update_responsive_woo_free_shipping_left_shortcode AJAX action that does not properly validate the content_rech_data parameter before processing it as a shortcode.