SQL injection vulnerability in calendar.php for Invision Power Board 1.3 allows remote attackers to execute arbitrary SQL commands via the m parameter, which sets the $this->chosen_month variable.
http://www.securitytracker.com/id?1008589
http://www.securityfocus.com/bid/9353
http://secunia.com/advisories/10530
http://forums.invisionpower.com/index.php?act=ST&f=1&t=108786