OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. From 3.8.0 to 4.10, in the function emsa_pkcs1_v1_5_encode() in core/drivers/crypto/crypto_api/acipher/rsassa.c, the amount of padding needed, "PS size", is calculated by subtracting the size of the digest and other fields required for the EMA-PKCS1-v1_5 encoding from the size of the modulus of the key. By selecting a small enough modulus, this subtraction can overflow. The padding is added as a string of 0xFF bytes with a call to memset(), and an underflowed integer will cause the memset() call to overwrite until OP-TEE crashes. This only affects platforms registering RSA acceleration.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-04-24
An unprotected memory-access operation in optee_os in TrustedFirmware Open Portable Trusted Execution Environment (OP-TEE) before 3.20 allows a physically proximate adversary to bypass signature verification and install malicious trusted applications via electromagnetic fault injections.
CVSS Score
6.4
EPSS Score
0.001
Published
2022-12-19
An issue was discovered in Trusted Firmware OP-TEE Trusted OS through 3.15.0. The OPTEE-OS CSU driver for NXP i.MX6UL SoC devices lacks security access configuration for wakeup-related registers, resulting in TrustZone bypass because the NonSecure World can perform arbitrary memory read/write operations on Secure World memory. This involves a v cycle.
CVSS Score
7.8
EPSS Score
0.001
Published
2021-12-07