ESF-IDF: Unvalidated Stack Pointer at the ESP-TEE Privilege-Switch Boundary

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. From 5.5.5 until 5.5.6, 6.0.4, and 6.1.1, the esp_tee trap entry in esp_tee_vectors_plic.S and esp_tee_vectors_clic.S saves a caller-controlled register frame through the REE-supplied stack pointer before switching to the trusted TEE stack or validating the pointer. A local unprivileged REE application can direct this machine-mode write into TEE-exclusive memory on ESP32-C5, ESP32-C6, ESP32-C61, and ESP32-H2 devices, breaking the REE/TEE isolation boundary and potentially corrupting TEE control-flow data for code execution, denial of service, or system crashes. Both secure-service ecall and interrupt entry paths contain the vulnerable ordering. This issue is fixed in version 5.5.6 and is scheduled to be fixed in versions 6.0.4 and 6.1.1.