Multiple cross-site scripting (XSS) vulnerabilities in Jay Eckles CGI Calendar 2.7 allow remote attackers to inject arbitrary web script or HTML via the year parameter in (1) index.cgi and (2) viewday.cgi.
https://exchange.xforce.ibmcloud.com/vulnerabilities/24946
http://www.vupen.com/english/advisories/2006/0764
http://www.securityfocus.com/archive/1/426198/100/0/threaded