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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-36219
• skalenetwork/sgxwallet@4e9b5b7
• https://github.com/skalenetwork/sgxwallet/releases