LLC Cache Attacks: Applicability and Countermeasures

Cache attacks have been demonstrated to be a big concern for security code designers by being able to recover a wide range of information, ranging from cryptographic keys to user privacy-related information. These attacks take advantage of the fact that two processes are utilizing the same hardware resource, thus leveraging unexpected leakages that can be exploited by a malicious user. More specifically, Last Level Cache (LLC) attacks make use of the fact that the LLC is shared across cores, thus being able to steal information from users located in different cores. This presentation describes the approaches that Flush and Reload and Prime and Probe take, together with the requirements that they need to successfully be launched. In addition, we evaluate different examples of everyday usage software that can be targeted by these kinds of attacks to violate our privacy. Further, this presentation expands on the scenarios in which both attacks can succeed, including but not limited to, IaaS and PaaS co-located VMs/processes, Web browsing javascript attacks, trusted execution environment attacks or cross smartphone application attacks. Finally, we evaluate the effectiveness of possible preventions at different levels of the system, including network level, software level, OS/hypervisor level, and hardware level countermeasures.