Cyber Resilience

CVE-2025-21291

High

Published: 14 January 2025

Published
14 January 2025
Modified
24 January 2025
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0225 85.0th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21291 is a high-severity Double Free (CWE-415) vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked in the top 15.0% 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 RA-5 (Vulnerability Monitoring and Scanning) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2025-21291 is a remote code execution vulnerability in the Windows DirectShow component. It carries a CVSS 3.1 base score of 8.8 with the vector string AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H and is also associated with CWE-415.

An unauthenticated remote attacker can exploit the flaw by convincing a user to open a specially crafted file or content over the network, resulting in arbitrary code execution with the privileges of the current user and full impact on confidentiality, integrity, and availability.

Microsoft has published an advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21291 that addresses the issue. The EPSS score remains flat at 0.0225 with no material increase since disclosure.

EU & UK References

Vulnerability details

Windows Direct Show Remote Code Execution Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1204 User Execution Execution
An adversary may rely upon specific actions by a user in order to gain execution.
Why these techniques?

Client-side RCE in Windows DirectShow multimedia framework with network vector and required user interaction directly maps to exploitation for client execution and user execution of malicious content.

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

CVEs Like This One

CVE-2025-21201Same product: Microsoft Windows 10 1809
CVE-2026-32074Same product: Microsoft Windows 10 1809
CVE-2026-32069Same product: Microsoft Windows 10 1809
CVE-2025-49724Same product: Microsoft Windows 10 1809
CVE-2026-20832Same product: Microsoft Windows 10 1809
CVE-2026-33824Same product: Microsoft Windows 10 1809
CVE-2026-33838Same product: Microsoft Windows 10 1809
CVE-2026-26163Same product: Microsoft Windows 10 1809
CVE-2025-62215Same product: Microsoft Windows 10 1809
CVE-2025-21239Same product: Microsoft Windows 10 1809

Affected Assets

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 11 22h2
≤ 10.0.22621.4751
microsoft
windows 11 23h2
≤ 10.0.22631.4751
microsoft
windows server 2019
≤ 10.0.17763.6775
microsoft
windows server 2022
≤ 10.0.20348.3091
microsoft
windows server 2022 23h2
≤ 10.0.25398.1369

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

SI-2 requires timely flaw remediation, directly mandating application of Microsoft patches to eliminate the Windows DirectShow RCE vulnerability.

detect

RA-5 implements vulnerability scanning to identify systems affected by CVE-2025-21291 in the DirectShow multimedia framework.

prevent

SI-16 provides memory protections like ASLR and DEP that mitigate successful remote code execution even if the DirectShow vulnerability is exploited.

References