CVE-2025-21218: Windows Kerberos Denial of Service Vulnerability

Overview

Severity

High (CVSS 7.5)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

Category

Denial of Service

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2025-Jan

Released

2025-01-14

Last Updated

2025-01-16

EPSS Score

1.31% (percentile: 79.9%)

FAQ

How could an attacker exploit this vulnerability? An unauthenticated attacker could use a specially crafted application to leverage a protocol vulnerability in the Kerberos Key Distribution Center (KDC) Proxy Service to perform denial of service against the target.

Affected Products (13)

Windows

• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows Server 2025 (Server Core installation)
• Windows Server 2022, 23H2 Edition (Server Core installation)
• Windows Server 2025
• Windows Server 2016
• Windows Server 2016 (Server Core installation)

ESU

• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (7)

• 5050008
• 5049983
• 5050009
• 5049984
• 5049993
• 5050004
• 5050048

Acknowledgments

<a href="https://twitter.com/keyz3r0">k0shl</a> with <a href="https://www.cyberkl.com/">Kunlun Lab</a>

Revision History

• 2025-01-14: Information published.
• 2025-01-16: Updated FAQ information. This is an informational change only.