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IP security shortcomings unpicked
UK infrastructure watchdog issues RFC
The UK's Centre for the Protection of National Infrastructure has completed a study on the TCP protocol that underpins intenet communications.
The study is billed as the first comprehensive security assessment of the core protocol, but would actually better be described as a road map of where we are and a jumping-off point for further discussion.
As the study notes, the TCP/IP protocol was developed to allow the sharing of large servers on the ARPANET, the forerunner to the internet. "As a result, many protocol specifications focus only on the operational aspects of the protocols they specify, and overlook their security implications," CPNI reports.
Internet technologies have evolved but the core protocols have remained largely unchanged. Flaws in TCP/IP stacks have been identified, some based on mistakes in specific implementations but others based on far more deep-seated problems. These security problems were not collated, which has led to a situation where problems known to some computer security response teams or vendors are not known across the wider community.
"Known security problems have not always been addressed by all vendors. In addition, in many cases vendors have implemented quick 'fixes' to the identified vulnerabilities without a careful analysis of their effectiveness and their impact on interoperability," the CPNI warns.
"Producing a secure TCP/IP implementation nowadays is a very difficult task, in part because of the lack of a single document that serves as a security roadmap for the protocols."
The CPNI wants to see the creation of a paper that discusses the existing vulnerabilities affecting TCP/IP and possible countermeasures, alongside a discussion of their effectiveness in combating security threats from hackers, malware and the like. IT wants this to exist as a companion piece to the IETF specification, which was conceived in an environment quite distinct from the hostile environment of today's internet.
CPNI charts some of these vulnerabilities - and possible countermeasures - in its 130-page study, but is clear in stating the list is far from definitive.
"This document does not aim to be the final word on the security aspects of TCP. On the contrary, it aims to raise awareness about a number of TCP vulnerabilities that have been faced in the past, those that are currently being faced, and some of those that we may still have to deal with in the future," it states, adding that community feedback is more than welcome.
Security researcher Fernando Gont, who worked on the study and told us of its publication, writes: "I believe it is the first comprehensive security assessment of the TCP protocol that has ever been done."
CPNI's study can be found here (pdf). ®