The firmware does not sufficiently verify the authenticity of boot components before execution. Boot images are trusted based only on short 4-byte magic string checks such as "BTLD", "KRNL", and "RTFS", which can be trivially forged by an attacker. Because there is no cryptographic signature verification, trusted root, or enforced chain of trust, an attacker who can replace or modify boot components may supply malicious bootloader, kernel, or root filesystem images that are accepted as valid.

This weak verification allows unsigned or tampered firmware components to execute during the boot process, potentially giving an attacker persistent low-level control of the device. In an OT/ICS environment, this can undermine system integrity, bypass higher-level security controls, and create safety or availability risks if compromised firmware alters device behaviour.

Remediation:

Implement a proper secure boot chain. Each boot stage should cryptographically verify the next stage before execution using trusted public keys stored in ROM, OTP memory, TPM, secure element, or another protected trust anchor. Replace magic-string validation with digital signature verification, reject unsigned or invalid images, and ensure the ROM, bootloader, kernel, and root filesystem form a continuous chain of trust.