CVE-2020-1165 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists when Windows improperly handles calls to Clipboard Service, aka 'Windows Clipboard Service Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-1111, CVE-2020-1121, CVE-2020-1166.
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Analysis
by VulDB Data Team • 10/17/2020
The vulnerability identified as CVE-2020-1165 represents a critical elevation of privilege flaw within the Windows operating system that specifically targets the Clipboard Service functionality. This vulnerability stems from improper handling of clipboard service calls, allowing malicious actors to escalate their privileges from standard user level to SYSTEM level access. The flaw exists in the way Windows processes and validates clipboard service communications, creating a pathway for unauthorized code execution with the highest possible system privileges.
Technical analysis reveals that the vulnerability occurs during the processing of clipboard service requests where Windows fails to properly validate the security context and permissions associated with clipboard operations. The Clipboard Service in Windows is responsible for managing clipboard data across different applications and processes, but when handling certain service calls, it does not adequately verify the calling process's privileges or security boundaries. This improper validation creates an opportunity for attackers to craft malicious clipboard service requests that can bypass normal security restrictions and execute code with elevated privileges.
The operational impact of this vulnerability is severe and far-reaching within Windows environments. An attacker with low-privilege access could exploit this flaw to gain SYSTEM-level privileges, enabling them to perform actions such as installing malware, modifying system files, creating new user accounts, accessing sensitive data, and completely compromising the affected system. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise and consumer deployments. This elevation of privilege allows attackers to move laterally within networks and establish persistent access to critical systems.
From a cybersecurity perspective, this vulnerability aligns with CWE-276, which describes improper privilege management in software systems. The flaw represents a classic case of insufficient privilege checking in system services, where the security model fails to properly enforce access controls during inter-process communications. The vulnerability also maps to several ATT&CK techniques including privilege escalation through service exploitation and abuse of system privileges. Organizations should implement immediate mitigations including applying Microsoft security patches, monitoring clipboard service access patterns, and implementing additional security controls such as AppLocker policies to restrict clipboard service access. The vulnerability underscores the importance of proper input validation and privilege checking in system services, particularly those that handle inter-process communications and data sharing mechanisms.
This vulnerability demonstrates the critical importance of maintaining secure coding practices in system-level services and highlights the potential for seemingly benign functionality to become attack vectors when proper security controls are not implemented. The exploitation of such vulnerabilities often requires sophisticated techniques and understanding of Windows internals, making it a concern for both nation-state actors and organized cybercriminal groups. Organizations should conduct thorough vulnerability assessments and implement layered security approaches to protect against similar privilege escalation vulnerabilities in their Windows environments.