Cyber Posture

CVE-2025-21218

High

Published: 14 January 2025

Published
14 January 2025
Modified
27 January 2025
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0131 80.0th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21218 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Microsoft Windows Server 2012. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 20.0% 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 SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability).

Threat & Defense at a Glance

What attackers do: exploitation maps to Application or System Exploitation (T1499.004). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

SI-2 mandates timely flaw remediation, directly addressing CVE-2025-21218 by requiring patches for the Windows Kerberos DoS vulnerability.

preventdetect

SC-5 provides denial-of-service protection mechanisms such as rate limiting to mitigate remote unauthenticated exploitation causing resource exhaustion in Kerberos.

prevent

SC-6 ensures resource availability by protecting against uncontrolled consumption attacks like CWE-400 in the Windows Kerberos component.

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Direct remote unauthenticated exploitation of the Kerberos component causes application/system crash and DoS (availability impact).

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

NVD Description

Windows Kerberos Denial of Service Vulnerability

Deeper analysisAI

CVE-2025-21218 is a Denial of Service vulnerability in the Windows Kerberos authentication component. Published on January 14, 2025, it carries a CVSS v3.1 base score of 7.5 (High), with vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, and is associated with CWE-400 (Uncontrolled Resource Consumption).

An unauthenticated attacker can exploit this vulnerability remotely over the network with low complexity and no user interaction. Exploitation leads to a denial of service condition, causing high impact on system availability while having no effect on confidentiality or integrity.

The Microsoft Security Response Center provides vulnerability details and mitigation guidance, including patches, in their update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21218.

Details

CWE(s)

Affected Products

microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
≤ 10.0.14393.7699
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
microsoft
windows server 2025
≤ 10.0.26100.2894

CVEs Like This One

CVE-2025-21290Same product: Microsoft Windows Server 2012
CVE-2025-21289Same product: Microsoft Windows Server 2012
CVE-2025-21270Same product: Microsoft Windows Server 2012
CVE-2025-21300Same product: Microsoft Windows Server 2012
CVE-2025-21389Same product: Microsoft Windows Server 2012
CVE-2025-21251Same product: Microsoft Windows Server 2012
CVE-2025-21351Same product: Microsoft Windows Server 2016
CVE-2025-21330Same product: Microsoft Windows Server 2019
CVE-2025-21207Same product: Microsoft Windows Server 2019
CVE-2026-26154Same product: Microsoft Windows Server 2012

References