Towards Automated Integrity Protection of C++ Virtual Function Tables in Binary Programs

Web browsers are one of the most used, complex and popular software systems nowadays. They are prone to use-after-free vulnerabilites and this is the de-facto way to exploit them. From a technical point of view, an attacker uses a technique called vtable hijacking to exploit such bugs. More specifically, she crafts bogus virtual tables and lets a freed C++ object point to it in order to gain control over the program at virtual function call sites. In this paper, we present a novel approach towards mitigating and detecting such attacks against C++ binary code. We propose a static binary analysis technique to extract virtual function call site information in an automated way. Leveraging this information, we instru-ment the given binary executable and add runtime policy enforcements to thwart the illegal usage of these call sites. We implemented the proposed techniques in a prototype called T-VIP and successfully hardened three versions of Microsoft’s Internet Explorer and Mozilla Firefox. An evaluation with several zero-day exploits demonstrates that our method prevents all of them. Performance benchmarks both on micro and macro level indicate that the overhead is reasonable with about 2.2%, which is slightly higher compared to recent compiler-based approaches that address this problem.