[原文]Cross-site scripting vulnerability in calendar.php in ExtCalendar 1.0 and possibly other versions before 2.0 allows remote attackers to inject arbitrary web script or HTML via the (1) year, (2) month, (3) next, and (4) prev parameters.
ExtCalendar contains a flaw that allows a remote cross site scripting attack. This flaw exists because the application does not validate the 'year', 'month', 'next' or 'prev' variables upon submission to the calendar.php script. This could allow a user to create a specially crafted URL that would execute arbitrary code in a user's browser within the trust relationship between the browser and the server, leading to a loss of integrity.
Upgrade to version 2.0 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.