Exploiting Hardware Vulnerabilities to Attack Embedded System Devices: a Survey of Potent Microarchitectural Attacks

Cyber-Physical system devices nowadays constitute a mixture of Information Technology (IT) and Operational Technology (OT) systems that are meant to operate harmonically under a security critical framework. As security IT countermeasures are gradually been installed in many embedded system nodes, thus securing them from many well-know cyber attacks there is a lurking danger that is still overlooked. Apart from the software vulnerabilities that typical malicious programs use, there are some very interesting hardware vulnerabilities that can be exploited in order to mount devastating software or hardware attacks (typically undetected by software countermeasures) capable of fully compromising any embedded system device. Real-time microarchitecture attacks such as the cache side-channel attacks are such case but also the newly discovered Rowhammer fault injection attack that can be mounted even remotely to gain full access to a device DRAM (Dynamic Random Access Memory). Under the light of the above dangers that are focused on the device hardware structure, in this paper, an overview of this attack field is provided including attacks, threat directives and countermeasures. The goal of this paper is not to exhaustively overview attacks and countermeasures but rather to survey the various, possible, existing attack directions and highlight the security risks that they can pose to security critical embedded systems as well as indicate their strength on compromising the Quality of Service (QoS) such systems are designed to provide.