CVE-2020-1111 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-2020-1121, CVE-2020-1165, CVE-2020-1166.
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Analysis
by VulDB Data Team • 10/17/2020
The Windows Clipboard Service Elevation of Privilege Vulnerability represents a critical security flaw in Microsoft Windows operating systems that allows malicious actors to escalate their privileges from standard user level to system level access. This vulnerability specifically manifests when the Windows Clipboard Service handles certain types of calls, creating an opportunity for unauthorized code execution with elevated privileges. The flaw exists within the service's improper handling of input validation and privilege checks during clipboard operations, making it particularly dangerous for attackers seeking to gain administrative control over affected systems.
This vulnerability operates through a privilege escalation mechanism that leverages the clipboard service's insufficient validation of user input and system calls. When legitimate applications interact with the clipboard service, the system fails to properly verify the authenticity and privilege level of the calling processes, allowing malicious code to exploit this gap and execute with higher privileges than intended. The vulnerability's technical nature stems from improper access control implementation within the Windows kernel and user-mode components that manage clipboard functionality. Attackers can craft specific clipboard operations that trigger the flawed code path, potentially enabling them to execute arbitrary code with system-level privileges. The flaw affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise environments.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a persistent foothold for further exploitation within compromised systems. Once an attacker successfully exploits this vulnerability, they can access sensitive system resources, modify critical files, install malware, and potentially establish backdoors for continued access. The vulnerability's stealthy nature makes detection challenging since legitimate clipboard operations may mask malicious activity. Organizations running affected Windows versions face significant risk of data breaches, system compromise, and potential lateral movement within their networks. The vulnerability's classification under CWE-276 indicates improper privilege management, while its alignment with ATT&CK technique T1068 suggests privilege escalation through system binary manipulation. The impact is particularly severe in enterprise environments where a single compromised user account could lead to complete system takeover.
Mitigation strategies for this vulnerability require immediate patch deployment through Microsoft's security updates, as the primary fix involves correcting the clipboard service's privilege handling mechanisms and input validation routines. Organizations should implement network segmentation and access controls to limit potential exploitation paths, while monitoring for unusual clipboard activity or privilege escalation attempts. Security teams must also consider implementing application whitelisting policies to restrict execution of unauthorized code, particularly in high-risk environments. The vulnerability's exploitation typically requires user interaction or initial access through other attack vectors, making user education and security awareness programs important complementary measures. Regular system audits and vulnerability assessments should be conducted to identify any potential exploitation attempts, while endpoint detection and response solutions should be configured to monitor for suspicious clipboard service behavior and privilege escalation activities. Microsoft recommends immediate deployment of the relevant security patches and implementation of additional security controls to protect against potential exploitation of this critical privilege escalation vulnerability.