DeluxeBB 1.07 and earlier allows remote attackers to bypass SQL injection protection mechanisms via the login variable and certain other variables, by using lowercase "union select" or possibly other statements that do not match the uppercase "UNION SELECT."
http://www.vupen.com/english/advisories/2006/2879
http://www.securityfocus.com/archive/1/440435/100/0/threaded
http://securityreason.com/securityalert/1254
http://secunia.com/advisories/21116
http://lists.grok.org.uk/pipermail/full-disclosure/2006-July/047989.html