CVE-2020-8731 in Server Board
Summary
by MITRE
Incorrect execution-assigned permissions in the file system for some Intel(R) Server Boards, Server Systems and Compute Modules before version 1.59 may allow an authenticated user to potentially enable escalation of privilege via local access.
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Analysis
by VulDB Data Team • 11/09/2020
This vulnerability affects Intel server boards, server systems, and compute modules with firmware versions prior to 1.59, representing a critical privilege escalation risk within the system's file system permissions. The flaw stems from improper execution-assigned permissions that create potential pathways for authenticated users to gain elevated privileges through local access methods. This issue falls under the category of improper access control vulnerabilities, which are commonly classified as CWE-284 according to the Common Weakness Enumeration catalog. The vulnerability exists at the firmware level, specifically within the system's boot process and file system management components, making it particularly dangerous as it can be exploited before the operating system fully initializes.
The technical implementation of this vulnerability involves the misconfiguration of file system permissions during the boot process or firmware initialization phase. An authenticated user with local access can exploit this weakness to modify critical system files or execute privileged operations that should normally be restricted. The flaw allows for unauthorized privilege escalation by manipulating file permissions or executing code with elevated privileges, which can lead to complete system compromise. This type of vulnerability is particularly concerning because it operates at a low level within the system architecture, often before traditional operating system security controls are fully active. The ATT&CK framework would categorize this under privilege escalation techniques, specifically targeting the 'Exploitation for Privilege Escalation' tactic where adversaries leverage system weaknesses to gain elevated access rights.
The operational impact of CVE-2020-8731 extends beyond simple privilege escalation, as it can enable attackers to gain persistent access to server infrastructure and potentially compromise entire network environments. Once an authenticated user successfully exploits this vulnerability, they can manipulate system configurations, install malicious software, or access sensitive data stored on the affected systems. The vulnerability affects enterprise server environments where multiple users may have legitimate local access, creating a significant risk for organizations with inadequate access controls or monitoring systems. The exploitation requires only local access and authentication, making it particularly dangerous in shared or multi-tenant server environments where physical access might be more readily available than previously assumed. Organizations running affected Intel server hardware should prioritize firmware updates to address this vulnerability, as the risk of exploitation increases with the availability of local authenticated access points.
Mitigation strategies should focus on immediate firmware updates to version 1.59 or later, which contain the necessary permission controls to prevent unauthorized privilege escalation. System administrators should also implement additional monitoring for unusual file system modifications and privilege changes on affected servers. The vulnerability demonstrates the importance of secure firmware development practices and proper access control implementation at all system levels, including the firmware and boot processes. Organizations should conduct comprehensive vulnerability assessments to identify all affected systems and implement layered security controls to reduce the attack surface. Regular firmware updates and security monitoring should be part of standard operational procedures to prevent similar vulnerabilities from being exploited in the future. The incident highlights the critical need for robust security practices in server infrastructure, particularly in environments where physical access controls may not be sufficient to prevent exploitation of low-level firmware vulnerabilities.