Cyber Resilience

CVE-2025-21420

High

Published: 11 February 2025

Published
11 February 2025
Modified
14 February 2025
KEV Added
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.3408 97.1th percentile
Risk Priority 36 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21420 is a high-severity Link Following (CWE-59) vulnerability in Microsoft Windows 10 1507. 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 2.9% 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 SI-2 (Flaw Remediation) and AC-6 (Least Privilege).

Deeper analysis

CVE-2025-21420 is an elevation of privilege vulnerability in the Windows Disk Cleanup Tool. It carries a CVSS 3.1 base score of 7.8 and is associated with CWE-59. The flaw permits a local attacker to elevate privileges on affected Windows systems.

An attacker with low privileges and local access can exploit the issue without user interaction, resulting in high impact to confidentiality, integrity, and availability. The attack vector is strictly local and does not cross trust boundaries.

Microsoft has published mitigation guidance and patch information in its advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21420. The current EPSS score of 0.3408, with a recorded peak of 0.4213, indicates moderate and sustained exploitation interest following disclosure.

EU & UK References

Vulnerability details

Windows Disk Cleanup Tool Elevation of Privilege Vulnerability

CWE(s)

Related Threats

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?

The CVE describes a local elevation of privilege vulnerability in Windows Disk Cleanup Tool via improper link resolution (CWE-59), allowing low-privileged attackers to gain full system control. This directly maps to Exploitation for Privilege Escalation.

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

CVEs Like This One

CVE-2025-21419Same product: Microsoft Windows 10 1507
CVE-2025-21373Same product: Microsoft Windows 10 1507
CVE-2025-21391Same product: Microsoft Windows 10 1507
CVE-2025-21331Same product: Microsoft Windows 10 1507
CVE-2026-25187Same product: Microsoft Windows 10 1607
CVE-2025-49687Same product: Microsoft Windows 10 1507
CVE-2025-21281Same product: Microsoft Windows 10 1507
CVE-2025-24044Same product: Microsoft Windows 10 1507
CVE-2025-21378Same product: Microsoft Windows 10 1507
CVE-2025-21293Same product: Microsoft Windows 10 1507

Affected Assets

microsoft
windows 10 1507
≤ 10.0.10240.20915 · ≤ 10.0.10240.20915
microsoft
windows 10 1607
≤ 10.0.14393.7785 · ≤ 10.0.14393.7785
microsoft
windows 10 1809
≤ 10.0.17763.6893 · ≤ 10.0.17763.6893
microsoft
windows 10 21h2
≤ 10.0.19044.5487
microsoft
windows 10 22h2
≤ 10.0.19045.5487
microsoft
windows 11 22h2
≤ 10.0.22621.4890
microsoft
windows 11 23h2
≤ 10.0.22631.4890
microsoft
windows 11 24h2
≤ 10.0.26100.3194
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
≤ 10.0.14393.7785
+4 more product configuration(s) — see NVD for full list

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly remediates the improper link resolution vulnerability in the Windows Disk Cleanup Tool by requiring timely application of the Microsoft security update.

prevent

Enforces least privilege on user accounts and processes, limiting the scope and impact of local low-privilege attackers attempting to exploit the elevation vulnerability.

prevent

Implements memory protections such as non-executable memory and ASLR to mitigate arbitrary code execution that may result from successful privilege escalation via improper file access.

References