source: https://www.securityfocus.com/bid/17903/info
MultiCalendars is prone to an SQL-injection vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input before using it in an SQL query.
A successful exploit could allow an attacker to compromise the application, access or modify data, or exploit vulnerabilities in the underlying database implementation.
Version 3.0 is reported to be vulnerable; other versions may also be affected.
http://www.example.com/Demos/MC/all_calendars.asp?month=4&year=2006&cate=&cTYPE=1&calsids='%20or%20'='