CVE-2020-8705 in CSME
Summary
by MITRE • 11/12/2020
Insecure default initialization of resource in Intel(R) Boot Guard in Intel(R) CSME versions before 11.8.80, 11.12.80, 11.22.80, 12.0.70, 13.0.40, 13.30.10, 14.0.45 and 14.5.25, Intel(R) TXE versions before 3.1.80 and 4.0.30, Intel(R) SPS versions before E5_04.01.04.400, E3_04.01.04.200, SoC-X_04.00.04.200 and SoC-A_04.00.04.300 may allow an unauthenticated user to potentially enable escalation of privileges via physical access.
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Analysis
by VulDB Data Team • 12/06/2020
The vulnerability described in CVE-2020-8705 represents a critical security flaw within Intel's Boot Guard implementation across multiple firmware components including CSME, TXE, and SPS versions. This issue stems from insecure default initialization of system resources during the boot process, creating a significant attack surface that can be exploited by adversaries with physical access to affected systems. The vulnerability affects a wide range of Intel firmware versions spanning multiple generations, indicating a fundamental design flaw that requires comprehensive remediation across the entire Intel firmware ecosystem.
The technical flaw manifests in the improper initialization of hardware resources within Intel's Boot Guard framework, which is designed to provide secure boot capabilities and protect against unauthorized modifications to the system's boot process. When firmware components fail to properly initialize security-critical resources, they create opportunities for privilege escalation attacks that can bypass the intended security boundaries. This flaw specifically impacts the integrity verification mechanisms that should prevent unauthorized code execution during the boot sequence, allowing malicious actors to potentially inject code or modify system behavior through physical access points. The vulnerability operates at a fundamental level of system security, affecting the core boot process that establishes the trusted computing base for all subsequent operations.
From an operational impact perspective, this vulnerability presents a severe risk to organizations relying on Intel firmware security features, particularly those in environments where physical security cannot be guaranteed. The requirement for physical access to exploit this vulnerability does not diminish its severity, as physical access often indicates a compromised environment or insider threat scenario. Attackers with physical access could potentially modify firmware components, bypass secure boot mechanisms, and establish persistent backdoors within the system. The attack surface extends beyond simple privilege escalation to include potential complete system compromise, as the vulnerability affects core boot components that are essential for maintaining system integrity and security posture. This vulnerability directly impacts the principles of integrity and confidentiality in the CIA triad, undermining the fundamental security guarantees that Boot Guard is designed to provide.
Mitigation strategies for CVE-2020-8705 require immediate firmware updates across all affected Intel CSME, TXE, and SPS versions, with particular attention to the specific version thresholds mentioned in the vulnerability description. Organizations should implement comprehensive firmware inventory management to identify all affected systems and prioritize remediation efforts based on risk assessment and physical security controls. The remediation process must include thorough testing of firmware updates to ensure compatibility with existing system configurations and avoid potential service disruptions. Additionally, security teams should enhance their physical security measures and implement monitoring procedures to detect unauthorized physical access attempts. This vulnerability aligns with ATT&CK technique T1068 which covers "Exploitation for Privilege Escalation" and CWE-284 which addresses "Improper Access Control" in the context of firmware security. Organizations should also consider implementing hardware-based security features such as Intel's Platform Trust Technology and ensure proper segregation of system components to limit the impact of potential exploitation. Regular security assessments and continuous monitoring of firmware integrity should become standard practice to prevent similar vulnerabilities from remaining undetected in the system's security infrastructure.