The SySS GmbH found out that the web server of VMware ESXi 6 is vulnerable to HTTP response injection attacks, as arbitrarily supplied URL parameters are copied in the HTTP header Location of the server response without sufficient input validation. Thus, an attacker can create a specially crafted URL with a specific URL parameter that injects attacker-controlled data to the response of the VMware ESXi web server. Depending on the context, this allows different attacks. If such a URL is visited by a victim, it may for example be possible to set web browser cookies in the victim’s web browser, execute arbitrary JavaScript code, or poison caches of proxy servers.