The The WPB Popup for Contact Form 7 – Showing The Contact Form 7 Popup on Button Click – CF7 Popup plugin for WordPress is vulnerable to arbitrary shortcode execution via wpb_pcf_fire_contact_form AJAX action in all versions up to, and including, 1.7.5. This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.