Cyber Posture

CVE-2025-21307

Critical

Published: 14 January 2025

Published
14 January 2025
Modified
24 January 2025
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.1077 93.4th percentile
Risk Priority 26 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21307 is a critical-severity Use After Free (CWE-416) vulnerability in Microsoft Windows 10 1507. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 6.6% 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 CM-7 (Least Functionality).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly remediates the use-after-free vulnerability in the Windows RMCAST driver by applying vendor-provided patches, preventing remote code execution.

prevent

Limits attack surface by configuring the system to disable the RMCAST driver and other unnecessary multicast transport capabilities when not required.

prevent

Monitors and controls network communications at boundaries to block unauthorized inbound multicast traffic that could trigger the RMCAST remote code execution vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
Why these techniques?

Remote unauthenticated RCE in network-exposed Windows driver directly enables exploitation of public-facing applications (T1190) and facilitates arbitrary code execution via command/scripting interpreters like PowerShell (T1059.001).

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

NVD Description

Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability

Deeper analysisAI

CVE-2025-21307 is a Remote Code Execution vulnerability affecting the Windows Reliable Multicast Transport Driver (RMCAST). Published on January 14, 2025, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), classifying it as critical severity and linking it to CWE-416.

The vulnerability enables remote exploitation over the network by unauthenticated attackers requiring no privileges or user interaction, with low attack complexity. Successful exploitation grants attackers remote code execution capabilities, resulting in high impacts to confidentiality, integrity, and availability.

The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21307 details mitigation strategies and available patches.

Details

CWE(s)

Affected Products

microsoft
windows 10 1507
≤ 10.0.10240.20890 · ≤ 10.0.10240.20890
microsoft
windows 10 1607
≤ 10.0.14393.7699 · ≤ 10.0.14393.7699
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 11 24h2
≤ 10.0.26100.2894
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
+5 more product configuration(s) — see NVD for full list

CVEs Like This One

CVE-2025-21298Same product: Microsoft Windows 10 1507
CVE-2025-21406Same product: Microsoft Windows 10 1507
CVE-2025-21296Same product: Microsoft Windows 10 1507
CVE-2025-21295Same product: Microsoft Windows 10 1507
CVE-2025-24072Same product: Microsoft Windows 10 1507
CVE-2025-50177Same product: Microsoft Windows 10 1507
CVE-2025-47986Same product: Microsoft Windows 10 1507
CVE-2025-24044Same product: Microsoft Windows 10 1507
CVE-2025-21281Same product: Microsoft Windows 10 1507
CVE-2025-24046Same product: Microsoft Windows 10 1507

References