CVE-2020-0657 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists when the Windows Common Log File System (CLFS) driver improperly handles objects in memory, aka 'Windows Common Log File System Driver Elevation of Privilege Vulnerability'.
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Analysis
by VulDB Data Team • 03/29/2024
The Windows Common Log File System CLFS driver vulnerability represents a critical elevation of privilege flaw that stems from improper memory object handling within the operating system's logging infrastructure. This vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it particularly concerning for enterprise environments where these systems are prevalent. The issue lies within the kernel-mode driver component that manages common log file structures, creating a pathway for malicious actors to escalate their privileges from standard user level to system level access.
The technical root cause of this vulnerability resides in how the CLFS driver processes memory objects during log file operations. Specifically, the flaw occurs when the driver fails to properly validate or sanitize memory references during certain file system operations, allowing for potential memory corruption scenarios. This improper handling creates opportunities for attackers to manipulate memory structures and execute arbitrary code with elevated privileges. The vulnerability is categorized under CWE-121 as a stack-based buffer overflow condition, though the actual implementation involves more complex memory management issues within the kernel driver context. Attackers can exploit this weakness by crafting malicious input that triggers the vulnerable code path, potentially leading to privilege escalation without requiring authentication.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to gain complete system control and access to sensitive data. Once an attacker successfully exploits this vulnerability, they can execute malicious code with system-level privileges, potentially leading to full system compromise. The attack vector typically involves local user exploitation where an authenticated user can leverage the vulnerability to elevate their access rights. This makes the vulnerability particularly dangerous in environments where users have standard account privileges but require access to systems running vulnerable Windows versions. The exploitation can result in persistent backdoor access, data exfiltration, and further network reconnaissance activities that align with ATT&CK technique T1068 for privilege escalation and T1566 for social engineering through malicious file execution.
Mitigation strategies for this vulnerability require immediate patching of affected systems through Microsoft security updates, as the primary fix involves correcting the memory handling routines within the CLFS driver. Organizations should implement comprehensive vulnerability management processes to ensure timely deployment of security patches across all Windows systems. Additionally, system administrators should consider implementing additional security controls such as enabling Windows Defender Application Control or AppLocker to restrict execution of unauthorized code. Network segmentation and privilege minimization practices can help reduce the potential impact if exploitation occurs, while monitoring solutions should be configured to detect anomalous privilege escalation behaviors that might indicate exploitation attempts. The vulnerability also underscores the importance of kernel-mode driver security reviews and proper memory management practices in operating system components, as highlighted by industry standards for secure coding practices and the need for robust input validation in kernel-level code.