An improper neutralization of input during web page generation [CWE-79] vulnerability in FortiOS versions 7.0.0 to 7.0.7 and 7.2.0 to 7.2.3 may allow a remote, unauthenticated attacker to launch a cross site scripting (XSS) attack via the "redir" parameter of the URL seen when the "Sign in with FortiCloud" button is clicked.