Cross-site Scripting vulnerability in Mitsubishi Electric MC Works64 versions 4.04E (10.95.210.01) and prior and ICONICS MobileHMI versions 10.96.2 and prior allows a remote unauthenticated attacker to gain authentication information of an MC Works64 or MobileHMI and perform any operation using the acquired authentication information, by injecting a malicious script in the URL of a monitoring screen delivered from the MC Works64 server or MobileHMI server to an application for mobile devices and leading a legitimate user to access this URL.