CVE-2020-8755 in CSME
Summary
by MITRE • 11/12/2020
Race condition in subsystem for Intel(R) CSME versions before 12.0.70 and 14.0.45, Intel(R) SPS versions before E5_04.01.04.400 and E3_05.01.04.200 may allow an unauthenticated user to potentially enable escalation of privilege via physical access.
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Analysis
by VulDB Data Team • 12/06/2020
The vulnerability identified as CVE-2020-8755 represents a critical race condition flaw within Intel's management subsystems, specifically affecting Intel Converged Security and Management Engine (CSME) versions prior to 12.0.70 and 14.0.45, alongside Intel Server Platform Services (SPS) versions before E5_04.01.04.400 and E3_05.01.04.200. This vulnerability exists at the firmware level and operates within the core management engine that provides hardware-level security functions and system monitoring capabilities. The race condition occurs during specific operational sequences where timing-sensitive operations are not properly synchronized, creating a window of opportunity for malicious exploitation. The flaw is particularly concerning because it requires only physical access to the target system, eliminating the need for network connectivity or authentication credentials, which makes it significantly more dangerous than traditional network-based vulnerabilities. This type of vulnerability falls under CWE-362, which specifically addresses Race Conditions, and aligns with ATT&CK technique T1068, which covers Exploitation for Privilege Escalation. The management engine subsystem operates with elevated privileges and has direct access to system hardware components, making any compromise of this subsystem potentially catastrophic for overall system security.
The technical implementation of this race condition stems from improper synchronization mechanisms within the firmware code that manages the interaction between different security modules and system components. When legitimate operations occur in rapid succession, the timing-sensitive code paths that should execute sequentially fail to properly coordinate their execution, allowing for unexpected behavior that can be exploited by an attacker with physical access. The vulnerability manifests when an attacker can manipulate the timing of specific firmware operations to cause the system to transition into an insecure state. The flaw specifically impacts the authentication and authorization processes within the management engine, potentially allowing an unauthenticated attacker to bypass security checks that should normally prevent privilege escalation. This type of vulnerability is particularly challenging to detect and remediate because it operates at the firmware level where traditional software security controls and monitoring mechanisms may not be effective. The race condition creates a temporal window where the system's security state can be manipulated, and this window is typically very brief, making it difficult to reproduce in controlled environments while still providing sufficient opportunity for exploitation.
The operational impact of CVE-2020-8755 extends far beyond simple privilege escalation, as it fundamentally compromises the security architecture of affected systems. An attacker with physical access can potentially gain root-level access to the system's management engine, which provides control over critical system functions including firmware updates, hardware configuration changes, and security policy enforcement. This level of access allows for persistent backdoor installation, system monitoring, and the ability to evade traditional security controls that operate at the operating system level. The vulnerability affects enterprise servers and workstations that rely on Intel's management technologies, creating a significant risk for organizations with large deployments of affected hardware. The impact is particularly severe because the management engine operates independently of the main operating system, meaning that traditional endpoint protection solutions may not detect or prevent exploitation of this vulnerability. Organizations running affected systems face the risk of complete system compromise, data exfiltration, and potential lateral movement within their networks through the compromised management engine. The vulnerability also impacts the integrity of system firmware, potentially allowing attackers to modify or replace critical system components without detection.
Mitigation strategies for CVE-2020-8755 must address both the immediate vulnerability and the underlying architectural issues that make such race conditions possible. The primary recommendation is to upgrade affected systems to firmware versions that contain patches for this vulnerability, specifically Intel CSME versions 12.0.70 and 14.0.45, and SPS versions E5_04.01.04.400 and E3_05.01.04.200. Organizations should implement comprehensive firmware update procedures that include thorough testing in controlled environments before deployment to production systems. Physical security measures must be strengthened to prevent unauthorized access to affected systems, as the vulnerability requires physical presence to exploit. Network segmentation and monitoring should be enhanced to detect potential exploitation attempts, particularly focusing on unusual management engine activity or firmware modification attempts. System administrators should implement regular firmware integrity checks and establish baseline configurations that can detect unauthorized modifications. The vulnerability highlights the importance of secure coding practices in firmware development, specifically around race condition prevention and proper synchronization mechanisms. Organizations should also consider implementing hardware security modules or trusted platform modules that can provide additional layers of protection against firmware-level attacks. Regular security assessments of management subsystems should be conducted to identify and remediate similar vulnerabilities that may exist in other firmware components. The remediation process requires careful coordination between hardware vendors, system administrators, and security teams to ensure complete protection across all affected systems while minimizing operational disruption.