Vvveb: Unauthenticated reflected XSS in public product return form via customer_order_id

Vvveb is a powerful and easy to use CMS with page builder to build websites, blogs or ecommerce stores. Prior to 1.0.8.3, there is an unauthenticated reflected cross-site scripting (XSS) issue in the public product return form in Vvveb CMS. The customer_order_id POST parameter is inserted into the Order %s not found! error message when the order lookup fails, and that message is rendered in the frontend template without HTML escaping. As a result, attacker-controlled HTML/JavaScript executes in the submitting user's browser. This vulnerability is fixed in 1.0.8.3.