Complex Vulnerabilities and Highly Sophisticated Attacks

Abstract

In Chapter 6, vulnerability analysis focused on identifying the weaknesses of a network, starting with the basic principles that underscore the given network. In contrast, this chapter analyzes the key principles and assumptions that define the network itself, in an effort to discover the presence of fundamental weaknesses, if any, and the exact circumstances under which the network may be broken. Clearly, such vulnerabilities are highly complex and are likely to require sophisticated attacks. Consider IP networks, a key strength of which is resilience, stemming from the lack of a priori knowledge of the exact route of any IP packet. A key assumption underlying this resilience is that an IP router, upon intercepting an incident IP packet, forwards it in the general direction of its final destination node toward a subsequent IP node through the least congested link. When a perpetrator intercepts and deliberately discards an IP packet at an intermediate node, the assumption is abruptly broken. Given that the Internet has been in use for some time, the circumstances under which the fundamental assumptions break down are well known. However, for networks that are relatively recent, such circumstances may not be public knowledge, implying that someone, somewhere, may know precisely how to bring a network down.