Local Privilege Escalation Risk in Microsoft Windows DWM Core Library

Historical catalog analysis: CISA added this entry on May 13, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2025-30400 is a use-after-free vulnerability (CWE-416) located within the Desktop Window Manager (DWM) Core Library of Microsoft Windows. This flaw allows an attacker who already has authorized access to a system to elevate their privileges locally. In a healthcare context, local privilege escalation is a critical stage in an attack chain, as it can enable an actor to move from a limited user account to a higher-privileged state, potentially facilitating unauthorized access to electronic Protected Health Information (ePHI) or the deployment of ransomware.

Exposure and applicability

This vulnerability applies to systems running affected versions of Microsoft Windows. Because Windows is widely deployed across healthcare workstations, administrative terminals, and as the underlying operating system for various medical device controllers, the potential attack surface is broad.

It is important to note that this is a local privilege escalation flaw; it requires the attacker to already have some level of authorized access to the machine. This makes the vulnerability particularly relevant for shared clinical workstations or systems where multiple users possess limited credentials.

Remediation priorities

Our analysis suggests prioritizing remediation based on the criticality of the asset and its proximity to sensitive patient data. Since CISA added this vulnerability to the Known Exploited Vulnerabilities (KEV) catalog on May 13, 2025, there is evidence that the flaw may be targeted in the wild.

Healthcare security leaders should consider the following priority levels:
* High Priority: Systems with direct access to ePHI databases, domain controllers, and workstations used by clinicians for patient care.
* Medium Priority: Internal administrative systems and non-clinical back-office workstations.
* Coordinated Priority: Medical devices running Windows. These should not be patched independently; updates must be coordinated with clinical engineering and the device vendor to ensure patient safety and maintain regulatory certifications.

How to validate remediation

To reduce exposure, organizations should apply the mitigations provided by Microsoft. Validation of these efforts can be achieved through:
* Version Verification: Confirming that the installed Windows build version matches or exceeds the patched version specified in the vendor’s security update guide.
* Configuration Audits: Using authorized vulnerability scanning tools to identify systems that remain unpatched against CVE-2025-30400.

Note that while updating the software reduces the likelihood of exploitation, a version check alone does not guarantee total system security, as other configuration weaknesses may exist.

Limits and open questions

At this time, it is unknown whether this vulnerability has been utilized in specific ransomware campaigns. Additionally, while CISA has set a remediation deadline of June 3, 2025, for federal agencies, this date serves as a risk indicator rather than a legal requirement for private healthcare providers.

Residual risk remains for legacy systems that may no longer receive security updates or medical devices where vendor patches are not yet available. In these instances, compensating controls—such as strict limiting of local user permissions and enhanced endpoint monitoring—could reduce the likelihood of successful privilege escalation.

Source and editorial note

CVE-2025-30400: Microsoft Windows DWM Core Library Use-After-Free Vulnerability · Source date: May 13, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: May 16, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 12, 2026 at 00:50 UTC.

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