Cyber Posture

CVE-2025-21271

High

Published: 14 January 2025

Published
14 January 2025
Modified
27 January 2025
KEV Added
Patch
CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0028 51.1th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21271 is a high-severity Buffer Over-read (CWE-126) vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 48.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-6 (Least Privilege) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Privilege Escalation (T1068). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires timely flaw remediation through vendor patches, directly preventing exploitation of the known elevation of privilege vulnerability in the Windows Cloud Files Mini Filter Driver.

prevent

Enforces least privilege for processes and users, limiting the scope and impact of local low-privilege attackers exploiting CVE-2025-21271 for elevation.

prevent

Provides memory protections such as non-executable memory and isolation to mitigate buffer over-read (CWE-126) exploits in the driver that enable privilege escalation.

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

CVE describes a local EoP vulnerability in a Windows driver that is directly exploitable by low-privileged attackers to elevate to higher privileges (including SYSTEM).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability

Deeper analysisAI

CVE-2025-21271 is an Elevation of Privilege vulnerability in the Windows Cloud Files Mini Filter Driver. This flaw, published on 2025-01-14, carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and is associated with CWE-126 and NVD-CWE-noinfo. It affects Windows systems utilizing the Cloud Files Mini Filter Driver component.

A local attacker with low privileges can exploit this vulnerability due to its local attack vector and low complexity requirements, with no user interaction needed. Successful exploitation grants high impacts on confidentiality, integrity, and availability, enabling the attacker to elevate privileges, potentially achieving full system compromise.

Microsoft's Security Response Center provides an update guide detailing mitigation and patching information for CVE-2025-21271 at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21271.

Details

CWE(s)

Affected Products

microsoft
windows 10 1809
≤ 10.0.17763.6775 · ≤ 10.0.17763.6775
microsoft
windows 10 21h2
≤ 10.0.19044.5371
microsoft
windows 10 22h2
≤ 10.0.19045.5371
microsoft
windows server 2019
≤ 10.0.17763.6775
microsoft
windows server 2022
≤ 10.0.20348.3091

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References