Microsoft pptp vpn vulnerabilities Exploits in Action

Source code/Pseudo Code:
The following simple script requires netcat (nc) to function:
#!/bin/sh
nc 1723 < /dev/zero
The above code simply sends malformed packets to the target port 
(tcp/1723) .
For detailed log notes on this attack, please see the log notes section in 
the Additional Information portion of this document (before the Bibliography).
Exploit 2 Details
Name:
PPTP ATTACK #2 ipsend based DoS attack
Type:
DoS (Denial of Service)
Vulnerability Variants:
Another variant of the “Malformed PPTP Packet 
Stream” vulnerability
Operating Systems:
NT Server (supposedly affect all service packs)
Protocols/Services:
PPTP GRE protocol 47
Brief Description: 
System will quickly blue screen shortly after the attack 
begins, this usually only requires about 50 packets to crash the PPTP server.