Parlano MindAlign 5.0 and later versions allows remote attackers to list valid users via unknown vectors, aka the "User Enumeration" vulnerability.
https://exchange.xforce.ibmcloud.com/vulnerabilities/21821
http://www.securityfocus.com/bid/14562
http://www.niscc.gov.uk/niscc/docs/br-20050812-00673.html?lang=en