CVE-2020-17136 in Windows
Summary
by MITRE • 12/10/2020
, aka 'Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-17103, CVE-2020-17134.
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Analysis
by VulDB Data Team • 08/29/2025
The Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability represents a critical security flaw in Microsoft's operating system infrastructure that allows attackers to escalate their privileges from standard user level to administrative rights. This vulnerability specifically affects the cloud files mini filter driver component that manages cloud storage integration within Windows environments, enabling malicious actors to exploit a flaw in the driver's privilege handling mechanisms.
The technical exploitation of this vulnerability occurs through improper validation of input parameters within the cloud files mini filter driver, which operates at a kernel level within the Windows operating system. When a local attacker executes malicious code that interacts with the cloud files driver, the flaw allows for privilege escalation by manipulating the driver's behavior to grant elevated permissions. The vulnerability stems from inadequate access control checks and insufficient validation of user-mode inputs before they are processed by kernel-mode components, creating a path for unauthorized privilege elevation.
This flaw impacts all supported versions of Windows 10 and Windows Server 2019, with the most severe implications occurring on systems where users have legitimate access to cloud storage services. The operational impact extends beyond simple privilege escalation, as attackers can leverage this vulnerability to gain full system control, install malicious software, modify system files, and potentially establish persistent backdoors. The attack vector requires local system access but does not necessitate network connectivity or complex social engineering, making it particularly dangerous in environments where users may have legitimate cloud storage access.
The vulnerability aligns with CWE-269: Improper Privilege Management, which specifically addresses issues where software fails to properly enforce access controls and privilege boundaries. From an ATT&CK framework perspective, this vulnerability maps to T1068: Exploitation for Privilege Escalation, where adversaries leverage software flaws to gain elevated system privileges. The technique typically involves exploiting kernel-mode vulnerabilities to move from user-level processes to system-level execution, enabling comprehensive system compromise.
Microsoft addressed this vulnerability through security updates that implemented proper input validation and access control mechanisms within the cloud files mini filter driver. Organizations should prioritize immediate deployment of the relevant security patches and implement additional monitoring for suspicious file system activities. The mitigation strategy should include regular vulnerability assessments, network segmentation to limit local access, and enhanced logging of cloud storage integration activities. Security teams should also consider implementing behavioral analysis tools that can detect anomalous patterns consistent with privilege escalation attempts, particularly in cloud storage integration scenarios.