Memory error exploits rank among the most serious security threats. Of the plethora of memory error containment solutions proposed over the years, most have proven to be too weak in practice. Multi-Variant eXecution (MVX) solutions can potentially detect arbitrary memory error exploits via divergent behavior observed in diversified program variants running in parallel. However, none have found practical applicability in security due to their non-trivial performance limitations. In this paper, we present MvArmor, an MVX system that uses hardware-assisted process virtualization to monitor variants for divergent behavior in an efficient yet secure way. To provide comprehensive protection against memory error exploits, MvArmor relies on a new MVX-aware variant generation strategy. The system supports user-configurable security policies to tune the performance-security trade-off. Our analysis shows that MvArmor can counter many classes of modern attacks at the cost of modest performance overhead, even with conservative detection policies.

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Despite decades of research, buffer overflows still rank among the most dangerous vulnerabilities in unsafe languages such as C and C++. Compared to other memory corruption vulnerabilities, buffer overflows are both common and typically easy to exploit. Yet, they have proven so challenging to detect in real-world programs that existing solutions either yield very poor performance, or introduce incompatibilities with the C/C++ language standard.We present Delta Pointers, a new solution for buffer overflow detection based on efficient pointer tagging. By carefully altering the pointer representation, without violating language specifications, Delta Pointers use existing hardware features to detect both contiguous and non-contiguous overflows on dereferences, without a single check incurring extra branch or memory access operations. By focusing on buffer overflows rather than other vulnerabilities (e.g., underflows), Delta Pointers offer a unique checkless design to provide high performance while still maintaining compatibility. We show that Delta Pointers are effective in detecting arbitrary buffer overflows and, at 35% overhead on SPEC, offer much better performance than competing solutions. CCS CONCEPTS· Security and privacy → Systems security; Software and application security;

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We explore a new technique for safe patch fingerprinting to automate vulnerability scanning of network servers. Our technique helps automate the discovery of inputs that safely discriminate vulnerable from patched servers for the latest vulnerabilities. This enables rapid updates to vulnerability scanning tools as new software vulnerabilities are discovered, allowing administrators to scan and secure their networks more quickly. To ensure such scans are safe and ethical, we need to reject inputs with malicious side effects. We have implemented a framework, based on delta execution, which tests the discriminative property of such inputs, as well as their safety. We use a fuzzer to find promising candidate inputs to further automate the process. To illustrate the potential of this approach, we present a Heartbleed case study.