Modular Protections Against Non-Control Data Attacks

Cole Schlesinger, Karthik Pattabiraman, Nikhil Swamy, David Walker and Benjamin Zorn, Journal of Computer Security (JCS), November 2014 (Invited as one of the best papers of the CSF 2011 Conference) [ PDF ]

Abstract. This paper introduces YARRA, a conservative extension to C to protect applications from non-control data attacks. YARRA programmers specify their data integrity requirements by declaring critical data types and ascribing these critical types to important data structures. YARRA guarantees that such critical data is only written through pointers with the given static type. Any attempt to write to critical data through a pointer with an invalid type (perhaps because of a buffer overrun) is detected dynamically. We formalize YARRA’s semantics and prove the soundness of a program logic designed for use with the language. A key contribution is to show that YARRA’s semantics are strong enough to support sound local reasoning and the use of a frame rule, even across calls to unknown, unverified code. We evaluate a prototype implementation of a compiler and runtime system for YARRA by using it to harden four common server applications against known non-control data vulnerabilities. We show that YARRA successfully defends the applications against these attacks. In our initial experiments, we find that the performance impact of YARRA is small, provided the amount of critical data is small and the application is not compute intensive.

This is based on our CSF’11 conference paper.