The captive portal application in Cisco Identity Services Engine (ISE) allows remote attackers to discover cleartext usernames and passwords by leveraging unspecified use of hidden form fields in an HTML document, aka Bug ID CSCug02515.
http://www.securitytracker.com/id/1028965
http://tools.cisco.com/security/center/viewAlert.x?alertId=30524
http://tools.cisco.com/security/center/content/CiscoSecurityNotice/CVE-2013-3471