Network Attacks and Exploitation

Chapter 5Attacker Frictions

Ain't nothin' gonna break my stride.

Nobody's gonna slow me down, oh-no

I got to keep on moving

—Matthew Wilder, American musician, composer, and record producer

Long ago the Prussian general Carl von Clausewitz defined the frictions of war as the “only concept that more or less corresponds to the factors that distinguish real war from war on paper.” Frictions are the unseen forces that act against movement and progress. The textbook example is an unpredicted patch of mud that bogs down the advance of a tank.

Although there's no mud involved, Computer Network Exploitation shares a few characteristics with war. There are opposing sides that plan and execute objectives. There are differing levels of resources, expertise, and experience. The software, hardware, and network systems involved are dynamic and so complex as to contain elements of unpredictability. These similarities make the model of the frictions of war useful for understanding CNE.

By definition, frictions are not predictable. A predictable friction would simply be an obstacle: something that careful planning can avoid. A firewall is not a friction. Its effects are entirely foreseeable and testable. A change in the set of firewall rules, however, is, especially if there is no advanced warning.

Frictions cannot be avoided, but that does not mean you must face them in ignorance. Certain classes of frictions occur frequently enough that they are worth contemplating when formulating an offensive ...