Michael Franz

Alexios Voulimeneas, Dokyung Song, Per Larsen et al.

Multi-variant execution (MVX) systems amplify the effectiveness of software diversity techniques. The key idea is to run multiple diversified program variants in lockstep while providing them with the same input and monitoring their run-time behavior for divergences. Thus, adversaries have to compromise all program variants simultaneously to mount an attack successfully. Recent work proposed distributed, heterogeneous MVX systems that leverage different ABIs and ISAs to increase the diversity between program variants further. However, existing distributed MVX system designs suffer from high performance overhead due to time-consuming network transactions for the MVX system's operations. This paper presents dMVX, a novel hybrid distributed MVX design, which incorporates new techniques that significantly reduce the overhead of MVX systems in a distributed setting. Our key insight is that we can intelligently reduce the MVX operations that use expensive network transfers. First, we can limit the monitoring of system calls that are not security-critical. Second, we observe that, in many circumstances, we can also safely cache or avoid replication operations needed for I/O related system calls. Our evaluation shows that dMVX reduces the performance degradation from over 50% to 3.1% for realistic server benchmarks.

Zijo Kenjar, Tommaso Frassetto, David Gens et al.

Fault-injection attacks have been proven in the past to be a reliable way of bypassing hardware-based security measures, such as cryptographic hashes, privilege and access permission enforcement, and trusted execution environments. However, traditional fault-injection attacks require physical presence, and hence, were often considered out of scope in many real-world adversary settings. In this paper we show this assumption may no longer be justified. We present V0LTpwn, a novel hardware-oriented but software-controlled attack that affects the integrity of computation in virtually any execution mode on modern x86 processors. To the best of our knowledge, this represents the first attack on x86 integrity from software. The key idea behind our attack is to undervolt a physical core to force non-recoverable hardware faults. Under a V0LTpwn attack, CPU instructions will continue to execute with erroneous results and without crashes, allowing for exploitation. In contrast to recently presented side-channel attacks that leverage vulnerable speculative execution, V0LTpwn is not limited to information disclosure, but allows adversaries to affect execution, and hence, effectively breaks the integrity goals of modern x86 platforms. In our detailed evaluation we successfully launch software-based attacks against Intel SGX enclaves from a privileged process to demonstrate that a V0LTpwn attack can successfully change the results of computations within enclave execution across multiple CPU revisions.

Dokyung Song, Julian Lettner, Prabhu Rajasekaran et al.

The C and C++ programming languages are notoriously insecure yet remain indispensable. Developers therefore resort to a multi-pronged approach to find security issues before adversaries. These include manual, static, and dynamic program analysis. Dynamic bug finding tools --- henceforth "sanitizers" --- can find bugs that elude other types of analysis because they observe the actual execution of a program, and can therefore directly observe incorrect program behavior as it happens. A vast number of sanitizers have been prototyped by academics and refined by practitioners. We provide a systematic overview of sanitizers with an emphasis on their role in finding security issues. Specifically, we taxonomize the available tools and the security vulnerabilities they cover, describe their performance and compatibility properties, and highlight various trade-offs.