Résumé
The FLASH interface is a crucial component in modern Microcontrollers (MCUs), serving as an intermediary for transferring instructions between the processor and program memory. Previous studies have demonstrated the effectiveness of Electromagnetic Fault Injection (EMFI) and Laser Fault Injection (LFI) in disrupting the operation of FLASH accelerators, leading to instruction line replay and skip faults. However these studies are limited to the case of sequential code and to a single FLASH interface configuration of the target MCU. In this work, we present an investigation on the impact of Body Bias Injection (BBI) on the FLASH accelerator in a 32-bit MCU.The experiments confirm that BBI can similarly induce instruction line replay and skip faults. A detailed analysis of the fault manifestations under various operational configurations of the FLASH accelerator is provided. The study has also extended the fault model to the case of branch operation (non-sequential code).This research contributes a refined understanding of FLASH interface fault behavior under BBI, and highlights the security implication of the decorrelated design between the Program Counter and the FLASH interface.