Adversaries could bypass the secure-boot process and execute their own untrusted, malicious boot code.
As a part of a secure-boot process, the read-only-memory (ROM) code for a System-on-Chip (SoC) or other system fetches bootloader code from Non-Volatile Memory (NVM) and stores the code in Volatile Memory (VM), such as dynamic, random-access memory (DRAM) or static, random-access memory (SRAM). The NVM is usually external to the SoC, while the VM is internal to the SoC. As the code is transferred from NVM to VM, it is authenticated by the SoC's ROM code.
If the volatile-memory-region protections or access controls are insufficient to prevent modifications from an adversary or untrusted agent, the secure boot may be bypassed or replaced with the execution of an adversary's code.
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