A reflected cross-site scripting (XSS) vulnerability exists in the playerConfUrl parameter in the /defaultui/player/modern.html file for SCORM Engine versions < 20.1.45.914, 21.1.x < 21.1.7.219. The issue exists because there are no limitations on the domain or format of the url supplied by the user, allowing an attacker to craft malicious urls which can trigger a reflected XSS payload in the context of a victim's browser.