CVE-2020-8766 in SGX DCAP
Summary
by MITRE • 11/12/2020
Improper conditions check in the Intel(R) SGX DCAP software before version 1.6 may allow an unauthenticated user to potentially enable denial of service via adjacent access.
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Analysis
by VulDB Data Team • 12/06/2020
The vulnerability identified as CVE-2020-8766 resides within the Intel Software Guard Extensions Dynamic Configuration and Attestation (SGX DCAP) software ecosystem, specifically affecting versions prior to 1.6. This flaw represents a critical weakness in the attestation process that governs the trustworthiness of Intel SGX enclaves. The vulnerability manifests as an improper conditions check that undermines the integrity verification mechanisms designed to ensure only legitimate and secure enclaves can operate within the SGX environment. The affected software components are integral to the remote attestation process, which is fundamental to establishing trust between the SGX enclave and external parties in confidential computing scenarios.
The technical flaw stems from insufficient validation of security parameters during the attestation workflow, allowing an attacker with adjacent network access to manipulate the conditions check logic. This vulnerability specifically impacts the measurement and verification of enclave identity, potentially enabling an unauthenticated attacker to bypass critical security checks that should prevent unauthorized access to protected enclaves. The improper conditions check creates a pathway where malicious actors can craft specially crafted attestation requests that appear legitimate to the system while actually exploiting weaknesses in the verification process. This weakness directly violates the fundamental principles of secure attestation as defined in the Intel SGX architecture and can lead to complete compromise of the enclave security model.
From an operational perspective, this vulnerability presents a significant risk for systems relying on Intel SGX for confidential computing workloads, particularly in environments where adjacent network access is possible. The potential for denial of service attacks means that legitimate users and applications could be disrupted or completely prevented from utilizing SGX capabilities. Attackers could leverage this weakness to repeatedly trigger invalid attestation responses, causing system instability or complete service interruption. The impact extends beyond simple availability concerns as this vulnerability could also enable privilege escalation or data exposure in scenarios where the attestation process is used to establish access controls or secure communication channels.
Organizations should immediately implement mitigation strategies including upgrading to Intel SGX DCAP software version 1.6 or later, which contains the necessary patches to address the improper conditions check vulnerability. Network segmentation and access controls should be strengthened to limit adjacent access to systems running SGX software, particularly in environments where the vulnerability could be exploited. Security monitoring should be enhanced to detect anomalous attestation patterns that might indicate exploitation attempts. Additionally, system administrators should conduct thorough assessments of their SGX-dependent applications to ensure proper implementation of attestation security measures and consider implementing additional layers of verification beyond the base platform protections. The vulnerability aligns with CWE-284, which addresses improper access control, and represents a significant concern within the ATT&CK framework under the privilege escalation and defense evasion techniques categories.