Today more and more vulnerabilities in computer systems are found each day. Some of them are minor security holes but others affect the whole infrastructure of the internet. Take a look at “Hackers Hacked at Defcon” and you will notice that there is at least one major vulnerability in the TCP/IP implementation. Because TCP/IP is so important for modern network infrastructure the Centre for the Protection of National Infrastructure has written an article about major/potential security flaws in the TCP/IP protocol. Take a look at their security assessment of the TCP/IP protocol it is worth the read.