WRQ Reflection for Secure IT Windows Server 6.0 (formerly known as F-Secure SSH server) processes access and deny lists in a case-sensitive manner, when previous versions were case-insensitive, which might allow remote attackers to bypass intended restrictions and login to accounts that should be denied.
http://www.kb.cert.org/vuls/id/758054
http://support.wrq.com/techdocs/1910.html