CVE-2021-36219

An issue was discovered in SKALE sgxwallet 1.58.3. The provided input for ECALL 14 triggers a branch in trustedEcdsaSign that frees a non-initialized pointer from the stack. An attacker can chain multiple enclave calls to prepare a stack that contains a valid address. This address is then freed, resulting in compromised integrity of the enclave. This was resolved after v1.58.3 and not reproducible in sgxwallet v1.77.0.