On Runtime Software Security of TrustZone-M based IoT Devices
This addresses runtime software security for resource-constrained IoT devices, but it is incremental as it applies known attack methods to a new context.
The paper conducted the first security analysis of software vulnerabilities in TrustZone-M enabled IoT microcontrollers, identifying and validating attacks like buffer overflows and ROP on a SAM L11 MCU, and discussed mitigation strategies.
Internet of Things (IoT) devices have been increasingly integrated into our daily life. However, such smart devices suffer a broad attack surface. Particularly, attacks targeting the device software at runtime are challenging to defend against if IoT devices use resource-constrained microcontrollers (MCUs). TrustZone-M, a TrustZone extension for MCUs, is an emerging security technique fortifying MCU based IoT devices. This paper presents the first security analysis of potential software security issues in TrustZone-M enabled MCUs. We explore the stack-based buffer overflow (BOF) attack for code injection, return-oriented programming (ROP) attack, heap-based BOF attack, format string attack, and attacks against Non-secure Callable (NSC) functions in the context of TrustZone-M. We validate these attacks using the TrustZone-M enabled SAM L11 MCU. Strategies to mitigate these software attacks are also discussed.