CVE-2020-17028 in Windows
Summary
by MITRE • 11/11/2020
Windows Remote Access Elevation of Privilege Vulnerability This CVE ID is unique from CVE-2020-17025, CVE-2020-17026, CVE-2020-17027, CVE-2020-17031, CVE-2020-17032, CVE-2020-17033, CVE-2020-17034, CVE-2020-17043, CVE-2020-17044, CVE-2020-17055.
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Analysis
by VulDB Data Team • 12/05/2020
This vulnerability represents a critical elevation of privilege flaw in Microsoft Windows Remote Access services that allows authenticated attackers to escalate their privileges from standard user level to system level access. The issue specifically affects the Windows Remote Access service implementation and stems from improper validation of user credentials and access controls within the remote access subsystem. The vulnerability exists in the way Windows handles authentication and authorization processes for remote access connections, creating a pathway for malicious actors to bypass normal security boundaries and gain elevated privileges without requiring additional exploitation techniques. This flaw significantly impacts the security posture of affected systems by undermining the fundamental principle of least privilege that governs access control in Windows environments.
The technical root cause of CVE-2020-17028 lies in the improper handling of remote access authentication tokens and session management within the Windows Remote Access service component. When legitimate users establish remote connections through the Windows Remote Access service, the system fails to properly validate the integrity of authentication contexts, allowing attackers to manipulate or forge authentication data that would normally be restricted. This vulnerability specifically impacts the Windows Remote Access service implementation and affects systems where the Remote Access service is enabled and configured, particularly in enterprise environments where remote access capabilities are commonly deployed. The flaw operates at the kernel level of the Windows operating system, making it particularly dangerous as it can be exploited to gain complete system control without requiring additional exploitation primitives. The vulnerability is classified under CWE-284 which addresses improper access control, specifically targeting inadequate privilege management within network services. This weakness enables attackers to leverage legitimate remote access functionality to perform unauthorized privilege escalation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can be leveraged to establish persistent access to compromised systems and facilitate further lateral movement within networks. Once an attacker successfully exploits this vulnerability, they gain the ability to execute arbitrary code with system-level privileges, potentially allowing them to install backdoors, modify system files, access sensitive data, or establish persistent command and control channels. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it particularly concerning for enterprise environments where these operating systems are widely deployed. The exploitation of this vulnerability can lead to complete system compromise and data exfiltration, as attackers can manipulate system configurations and access protected resources that would normally be restricted to administrators. Security analysts have noted that this vulnerability is particularly dangerous because it can be exploited remotely without requiring physical access to the target system, making it a prime target for advanced persistent threat actors. The vulnerability aligns with ATT&CK technique T1068 which covers privilege escalation through the exploitation of system vulnerabilities, and specifically relates to the use of remote access services for unauthorized system access.
Microsoft has addressed this vulnerability through security updates that correct the authentication validation processes within the Windows Remote Access service. Organizations should prioritize applying these patches to mitigate the risk of exploitation, particularly in environments where remote access services are actively deployed. The recommended mitigation strategy involves implementing network segmentation to restrict access to remote access services, enabling multi-factor authentication where possible, and monitoring for unusual authentication patterns that might indicate exploitation attempts. Security teams should also conduct vulnerability assessments to identify systems running affected versions of Windows Remote Access services and ensure proper patch management procedures are in place. Additional defensive measures include implementing network access controls to limit remote access capabilities, regularly auditing remote access service configurations, and monitoring system logs for signs of privilege escalation attempts. The vulnerability serves as a reminder of the importance of maintaining up-to-date security patches and the critical need for continuous monitoring of remote access services that are essential for business operations but also represent significant security risks when improperly configured or unpatched.