SoK: “Plug & Pray” Today – Understanding USB Insecurity in Versions 1 through C Dave (Jing) Tian∗, Nolen Scaife∗, Deepak Kumary, Michael Baileyy, Adam Batesy, Kevin R. B. Butler∗ ∗University of Florida fdaveti, scaife, butlerg@ufl.edu yUniversity of Illinois at Urbana-Champaign fdkumar11, mdbailey,
[email protected] Abstract—USB-based attacks have increased in complexity in systematizing the defenses present in the USB ecosystem, we recent years. Modern attacks now incorporate a wide range of find that most defenses often focus on protecting a single layer, attack vectors, from social engineering to signal injection. To which proves ineffective against a suite of attacks that appear address these challenges, the security community has responded with a growing set of fragmented defenses. In this work, at many communication layers. In addition, misaligned goals we survey and categorize USB attacks and defenses, unifying between industry and academia further fragment the defense observations from both peer-reviewed research and industry. space. Commercial solutions focus on the prevention of data Our systematization extracts offensive and defensive primitives loss and anti-malware without regard for emerging attack that operate across layers of communication within the USB vectors, while research prototypes vary and are hamstrung by ecosystem. Based on our taxonomy, we discover that USB attacks often abuse the trust-by-default nature of the ecosystem, and the lack of built-in security building blocks in the existing transcend different layers within a software stack; none of USB specifications. As a result, research solutions often rely the existing defenses provide a complete solution, and solutions on new host and peripheral architectures that are unlikely to expanding multiple layers are most effective.