Multiple cross-site scripting (XSS) vulnerabilities in WebCalendar 1.2.0, and other versions before 1.2.5, allow remote attackers to inject arbitrary web script or HTML via the (1) tab parameter to users.php and the PATH_INFO to (2) day.php, (3) month.php, and (4) week.php.  NOTE: some of these details are obtained from third party information.