source: http://www.securityfocus.com/bid/700/info Novell client versions 3.0 and 3.01 for Windows platforms are vulnerable to a remotely exploitable vulnerability which could cause a denial of service. The client opens a listening tcp socket on port 427, to which if a SYN is sent, results in the machine locking with a "blue screen" error. The only solution from that point is to reset the affected computer. nmap -sS -p 427 <target>