Comprehensive Evaluation of RSB and Spectre Vulnerability on Modern Processors

Performance-enhancing mechanisms such as branch prediction, out-of-order execution, and return stack buffer (RSB) have been widely employed in today's modern processing units. Although successful in increasing the CPU performance, exploiting the design flaws and security bugs in these components have set the background for various types of microarchitectural attacks such as Spectre and Meltdown. While many attacks such as Meltdown and Spectre have been numerously implemented and analyzed on Intel processors, few researches have been carried out to evaluate their impact on ARM processors. Moreover, SpectreRSB vulnerability, the newer variant of spectre attack based on RSB, has been neglected in recent studies. In this work, we first evaluate the SpectreRSB vulnerability by implementing this attack on ARM processors, which, to the best of our knowledge, has not been implemented and analyzed on ARM processors. We further present a security evaluation of ARM processors by implementing different variants of Spectre-family attacks. By analyzing the results obtained from various experiments, we evaluate ARM processors security regarding their diverse microarchitectural designs. We also introduce a high throughput and noise-free covert channel, based on the RSB structure. Based on our experiments, the throughput of the covert channel is 94.19KB/s with negligible error.