SQL injection vulnerability in index.php in ActiveCampaign KnowledgeBuilder 2.4 and earlier allows remote attackers to execute arbitrary SQL commands via the article parameter.
http://www.vupen.com/english/advisories/2005/2587
http://secunia.com/advisories/17732
http://pridels0.blogspot.com/2005/11/activecampaign-knowledgebuilder-vuln.html