Microsoft pptp vpn vulnerabilities Exploits in Action

VPND (Virtual Private Network Daemon)
VPND description 
http://sunsite.dk/VPNd/
 
Overview states: 
“The virtual private network daemon VPNd is a daemon which 
connects two networks on network level either via TCP/IP or a (virtual) leased 
line attached to a serial interface. All data transfered between the two networks 
are encrypted using the unpatented free 
Blowfish
encryption algorithm.”
L2F (Cisco Layer 2 Forwarding protocol)
RFC 2341 
http://www.faqs.org/rfcs/rfc2341.html
RFC 2341 Abstract states:
“Virtual dial-up allows many separate and 
autonomous protocol domains to share common access infrastructure including 
modems, Access Servers, and ISDN routers.  Previous RFCs have specified 
protocols for supporting IP dial-up via SLIP [1] and multiprotocol dial-up via
PPP [2]. “ ”…Layer Two Forwarding protocol (L2F) which permits the tunneling 
of the link layer (i.e., HDLC, async HDLC, or SLIP frames) of higher level 
protocols.  Using such tunnels, it is possible to divorce the location of the initial 
dial-up server from the location at which the dial-up protocol connectionis 
terminated and access to the network provided.”