How USB Does (and Doesn’t) Work: A Security Perspective

USB devices are easy to take for granted: They’re innocuous by their nature (who’s afraid of a keyboard?) and by their ubiquity. However, the architecture of the Universal Serial Bus ecosystem is surprisingly complex and deeply embedded in modern operating systems. Furthermore, having risen to awareness on the backs of traditionally “dumb” devices like keyboards and mice, the features of the USB protocol that very much resemble wide-area networking protocols can be underappreciated. This combination of complexity, embeddedness, and underappreciation is the unholy trinity of security “features.”