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. Prior to version 4.11.0, on many of the ECDH shared secret paths, the public key isn't verified to be a point on the correct curve. By passing approximately 30-40 crafted public keys to OP-TEE, the private key can be reconstructed by a normal world attacker. When calling TEE_DeriveKey the public key is provided with full X and Y values, but the (X, Y) point might not satisfy the `Y^2 == X^3 + aX + b mod P` math for the specific curve that is used. When those public keys aren't rejected, the attacker can select public keys such that each DeriveKey call will leak `d % r` where `d` is the private key and `r` comes from the relationship between the correct curve and the attacker selected curve. With enough leaked data the Chinese remainder theorem can be used to recover the full private key. Version 4.11.0 fixes the issue.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-06-03
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