Verify&Revive: Secure Detection and Recovery of Compromised Low-end Embedded Devices
Mahmoud Ammar, Bruno Crispo · Annual Computer Security Applications Conference · 2020
Tiny and specialized computing platforms, so-called embedded or Internet of Things (IoT) devices, are increasingly used in safety- and privacy-critical application scenarios. A significant number of such devices offer limited or no security features, making them attractive targets for a wide variety of cyber attacks, exemplified by malware infestations. One key component in securing these devices is establishing a root of trust, which is typically attained via remote attestation (RA), a security service that aims to ascertain the current state of a remote device and detect any malicious tampering. Although several (software-based, hardware-based, and hybrid) RA approaches have been proposed to address this problem, two main issues remain, regardless of the type of RA. First, all but one of the existing RA approaches are vulnerable to Time-Of-Check Time-Of-Use (TOCTOU) attack, where a transient malware may infect the corresponding embedded device between two consecutive RA routines without being detected. Second, little attention has been devoted to efficiently and securely rescuing devices that are determined to be compromised, increasing the maintenance cost of IoT deployments, especially in industrial control systems, where (re-)deploying a new device is often a cost-sensitive operation.