CVE-2026-33662
Description
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 Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Threat Intelligence
Weaknesses 1
Affected Products 1
| Vendor | Product | Version | Range |
|---|---|---|---|
| trustedfirmware | op-tee | * | ≥3.8.0 – ≤4.10.0 |
References 1
- github.com https://github.com/OP-TEE/optee_os/security/advisories/GHSA-4cf8-v5g3-73gr
Remediation
- github.com https://github.com/OP-TEE/optee_os/security/advisories/GHSA-4cf8-v5g3-73gr