CVE-2020-0777 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists when the Windows Work Folder Service improperly handles file operations, aka 'Windows Work Folder Service Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-0797, CVE-2020-0800, CVE-2020-0864, CVE-2020-0865, CVE-2020-0866, CVE-2020-0897.
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Analysis
by VulDB Data Team • 04/10/2024
The Windows Work Folder Service vulnerability identified as CVE-2020-0777 represents a critical elevation of privilege flaw that exploits improper handling of file operations within the Windows operating system. This vulnerability specifically targets the Work Folder Service component which enables users to synchronize files between their local devices and corporate servers through a centralized file sharing mechanism. The flaw allows authenticated attackers with limited system access to escalate their privileges and gain higher-level system permissions, potentially leading to complete system compromise. The vulnerability exists in the service's file operation handling mechanisms, where inadequate input validation and access control checks permit malicious file manipulation that bypasses normal security boundaries.
The technical exploitation of this vulnerability occurs through manipulation of file operations within the Work Folder Service context. When the service processes file synchronization requests, it fails to properly validate file paths, permissions, or operation sequences, creating opportunities for privilege escalation attacks. Attackers can leverage this weakness by crafting specific file operations that exploit the service's inadequate validation logic, potentially allowing them to execute arbitrary code with elevated privileges. This flaw falls under the CWE-264 category of "Permissions, Privileges, and Access Controls" and aligns with ATT&CK technique T1068 which covers "Exploitation for Privilege Escalation." The vulnerability demonstrates a classic path traversal and access control bypass pattern where the service fails to properly enforce security boundaries during file operation processing.
The operational impact of CVE-2020-0777 extends beyond immediate privilege escalation to potentially enable broader system compromise and data exfiltration capabilities. Organizations utilizing Windows Work Folder Services are particularly at risk since this vulnerability can be exploited by attackers who have already gained some level of access to the system. Once successfully exploited, the elevated privileges could allow attackers to modify critical system files, install persistent backdoors, access sensitive corporate data, or establish footholds for further lateral movement within the network. The vulnerability affects Windows 10 versions and Windows Server 2019 systems, making it particularly concerning for enterprise environments that rely heavily on file synchronization services. Security researchers have noted that the attack surface is significant due to the widespread use of Work Folder Services in corporate environments where file sharing and synchronization are essential business functions.
Mitigation strategies for CVE-2020-0777 should focus on immediate patch deployment and operational security enhancements. Microsoft released security updates in the May 2020 Patch Tuesday updates that address this vulnerability through improved file operation validation and access control mechanisms within the Work Folder Service. Organizations should prioritize applying these patches across all affected systems, particularly those running Windows 10 and Windows Server 2019 environments. Additional protective measures include implementing network segmentation to limit access to Work Folder Service endpoints, disabling the service when not required, and monitoring for suspicious file operations within Work Folder contexts. Security teams should also consider implementing enhanced logging and monitoring for file operations that occur through the Work Folder Service to detect potential exploitation attempts. The vulnerability's remediation aligns with industry best practices for privilege escalation protection and follows the principle of least privilege enforcement as outlined in cybersecurity frameworks such as NIST SP 800-53 and ISO 27001 standards.