Executive brief
OP-TEE is a secure operating system used on Arm-based devices to protect sensitive data and cryptographic keys from the main Linux system. A vulnerability in how it handles certain cryptographic operations allows a local attacker to recover private encryption keys by providing specially crafted data. This could lead to the compromise of secure communications or protected data on affected mobile and embedded devices.
Technical details
A vulnerability exists in OP-TEE's ECDH implementation where the TEE_DeriveKey function fails to validate that a provided public key (X, Y) resides on the intended elliptic curve. By submitting 30-40 crafted public keys that do not satisfy the curve equation, a 'normal world' attacker with local access can observe leaked residues of the private key. Using the Chinese Remainder Theorem, the attacker can reconstruct the full private ECC key. The issue affects implementations using libtomcrypt and CAAM drivers, while MbedTLS and certain hardware-backed implementations (like STM32) are reportedly unaffected. The vulnerability is addressed in version 4.11.0 by validating that ECC public keys are on the curve.
Affected products
- OP-TEE OP-TEE OS < 4.11.0
Timeline
- 2026-04-22: disclosed: Report received by vendor
- 2026-04-24: other: Security issue and severity confirmed
- 2026-06-03: patched: Fix published in version 4.11.0
- 2026-06-03: advisory: Public disclosure of CVE-2026-45614