The device does not contain or contains incorrectly implemented circuitry or sensors to detect and mitigate voltage and clock glitches and protect sensitive information or software contained on the device.
A device might support features such as secure boot which are supplemented with hardware and firmware support. This involves establishing a chain of trust, starting with an immutable root of trust by checking the signature of the next stage (culminating with the OS and runtime software) against a golden value before transferring control. The intermediate stages typically set up the system in a secure state by configuring several access control settings. Similarly, security logic for exercising a debug or testing interface may be implemented in hardware, firmware, or both. A device needs to guard against fault attacks such as voltage glitches and clock glitches that an attacker may employ in an attempt to compromise the system.
Threat Mapped score: 3.0
Industry: Finiancial
Threat priority: P2 - Serious (High)
CVE: CVE-2019-17391
Lack of anti-glitch protections allows an attacker to launch a physical attack to bypass the secure boot and read protected eFuses.
CVE: CVE-2021-33478
IP communication firmware allows access to a boot shell via certain impulses
N/A
| Phase | Note |
|---|---|
| Operation | N/A |
Intro: Below is a representative snippet of C code that is part of the secure-boot flow. A signature of the runtime-firmware image is calculated and compared against a golden value. If the signatures match, the bootloader loads runtime firmware. If there is no match, an error halt occurs. If the underlying hardware executing this code does not contain any circuitry or sensors to detect voltage or clock glitches, an attacker might launch a fault-injection attack right when the signature check is happening (at the location marked with the comment), causing a bypass of the signature-checking process.
Body: After bypassing secure boot, an attacker can gain access to system assets to which the attacker should not have access.
... if (signature_matches) // <-Glitch Here { load_runtime_firmware(); } else { do_not_load_runtime_firmware(); } ...