Executive brief
Caliptra Core Runtime Firmware, which provides security services for hardware root-of-trust, contains a flaw in how it verifies firmware updates. An attacker with high privileges could bypass security checks to load unauthorized or malicious firmware onto the system during an update process. This could lead to a complete compromise of the hardware's security and the data it protects.
Technical details
A vulnerability exists in the Caliptra Core Runtime Firmware within the `ActivateFirmwareCmd::activate_fw` module (specifically `runtime/src/activate_firmware.rs`). The root cause is an incorrect check of a function return value, which causes the firmware authorization check to be silently discarded during an MCU hitless update. This creates a Time-of-Check Time-of-Use (TOCTOU) risk where unauthorized MCU firmware can be loaded and executed without detection. Exploitation requires high privileges and an adjacent network position. The issue is addressed in patched versions 2.0.2 and 2.1.1.
Affected products
- Caliptra Core Runtime Firmware 2.0.0, 2.0.1, 2.1.0
Timeline
- 2026-06-23: advisory: GitHub Security Advisory published
- 2026-06-24: disclosed: NVD publication date