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An Initial Investigation of Protocol Customization

Attacks exploiting design or implementation flaws of particular features in popular protocols are becoming prevalent and have led to severe security impacts on a majority of software systems. Protocol customization as a general approach to specialize a standard protocol holds significant promise in reducing such attack surfaces in common protocols. In this work, we perform an initial investigation of applying protocol customization practices to reduce the attack surface of standard protocols. Our characterization study on 20 medium or high-impact common vulnerability exposures (CVEs) published in recent years indicates that some forms of customization have been supported in existing protocol software, but were implemented with huge manual effort and in an ad-hoc manner. More systematic and automated ways of protocol customization are awaited to generalize common customization practices across protocols. To work towards this goal, we identify key research challenges for the support of systematic and sufficiently automated protocol customization through real-world case study on popular protocol software, and propose an access control framework as a principled solution to unify existing protocol customization practices. We also present a preliminary design of a protocol customization system based on this design principle. Preliminary evaluation results demonstrate that our proposed system supports common customization practices for a majority of real-world protocol vulnerabilities in a systematic way.