OP-TEE's optee_os versions before 4.11.0 contain an improper verification of cryptographic signatures (CWE-347) in ECDH shared secret derivation. Specifically, the public key points (X, Y) provided during TEE_DeriveKey calls are not checked to confirm they satisfy the elliptic curve equation for the expected curve. An attacker can supply approximately 30-40 specially crafted public keys that do not lie on the correct curve, causing leakage of partial private key information (d % r) with each call. Using these leaked residues and the Chinese remainder theorem, the attacker can reconstruct the full private key. This vulnerability compromises the confidentiality of private keys used in OP-TEE's cryptographic operations. Version 4.11.0 of optee_os addresses this by properly verifying public keys.

An attacker with the ability to invoke TEE_DeriveKey and supply crafted public keys can recover the private key used in elliptic curve cryptography within OP-TEE. This compromises the confidentiality of cryptographic keys, potentially undermining the security guarantees of the Trusted Execution Environment. The vulnerability does not affect integrity or availability directly and requires local attacker privileges with low user privileges and high attack complexity. There are no known exploits in the wild as of the published date.

Upgrade OP-TEE optee_os to version 4.11.0 or later, where the issue is fixed by proper verification of public keys on the correct elliptic curve. Since no official patch links or vendor advisory are provided, confirm the upgrade path from OP-TEE project resources. Patch status is not yet confirmed beyond the version fix note; check the OP-TEE vendor advisory for current remediation guidance.