Intel has addressed concerns following revelations by security researcher Mark Ermolov about vulnerabilities in the company’s Software Guard Extensions (SGX) data protection technology. Ermolov, affiliated with the Russian cybersecurity firm Positive Technologies, announced that his team successfully extracted cryptographic keys linked to Intel SGX, which is designed to safeguard code and data from both software and hardware attacks through its trusted execution environment, known as an enclave. He identified the extraction of the SGX Fuse Key0 (FK0), also referred to as the Root Provisioning Key, and its associated Root Sealing Key (FK1) as significant threats that could compromise the entire security framework of SGX.
Pratyush Ranjan Tiwari, a cryptography expert from Johns Hopkins University, elaborated on the implications of this research, emphasizing that access to FK0 could allow an attacker to decrypt sealed data and produce counterfeit attestation reports, thereby undermining SGX’s intended security guarantees. While the affected processors, such as Apollo Lake and Gemini Lake, have reached the end of their life cycles, they remain prevalent in embedded systems, raising concerns about the continued risk these vulnerabilities pose.
In response to these claims, Intel clarified that the research was conducted on systems to which the researchers had physical access, and these systems were not equipped with the latest mitigations or configurations. Intel noted that the vulnerabilities exploited were previously mitigated and dated back to 2017, stating that the findings were not unexpected. Furthermore, the key extracted by the researchers remains encrypted, necessitating that the encryption must be broken for malicious use, which would only be applicable to the specific system involved in the attack.
Ermolov acknowledged that while the extracted key is encrypted with a Fuse Encryption Key (FEK) or Global Wrapping Key (GWK), he is optimistic about the potential for decryption, referencing previous successful attempts to obtain similar keys. He also pointed out that the GWK is shared across all chips of the same microarchitecture, suggesting that if an attacker were to acquire the GWK, they could potentially decrypt the FK0 for any chip within that architecture. Ermolov concluded that the primary risk of the leak of the Intel SGX Root Provisioning Key lies in the ability to forge Intel SGX Remote Attestation, which is meant to verify that software is securely operating within an Intel SGX enclave.
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