Multiple cross-site scripting (XSS) vulnerabilities in checkout.php in Avactis Shopping Cart 1.8.0 and 1.8.1 allow remote attackers to inject arbitrary web script or HTML via the (1) step_id and (2) CHECKOUT_CZ_BLOWFISH_KEY parameters.
https://exchange.xforce.ibmcloud.com/vulnerabilities/44929
http://www.securityfocus.com/bid/31054
http://www.avactis.com/forums/index.php?showtopic=3577