Feb 2025: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
CVE-2025-21418 Published on February 11, 2025

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

Vendor Advisory NVD

Known Exploited Vulnerability

This Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Microsoft Windows Ancillary Function Driver for WinSock contains a heap-based buffer overflow vulnerability that allows for privilege escalation, enabling a local attacker to gain SYSTEM privileges.

The following remediation steps are recommended / required by March 4, 2025: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Weakness Type

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Products Associated with CVE-2025-21418

Want to know whenever a new CVE is published for Microsoft products? stack.watch will email you.

Microsoft Windows Server 2008

Microsoft Windows Server 2012

Microsoft Windows Server 2016

Microsoft Windows Server 2019

Microsoft Windows Server 2022

Microsoft Windows 11

Microsoft Windows 10

Microsoft Windows 11 23h2

Microsoft Windows Server 2022 23h2

Microsoft Windows 11 24h2

Microsoft Windows Server 2025

Microsoft Windows

Microsoft Windows Server 23h2

Microsoft Windows 10 1507

Microsoft Windows Server 2008 Sp2

Microsoft Windows Server 2008 R2

Microsoft Windows Server 2012 R2

Affected Versions

Microsoft Windows 10 Version 1507:

Version 10.0.10240.0 and below 10.0.10240.20915 is affected.

Microsoft Windows 10 Version 1607:

Version 10.0.14393.0 and below 10.0.14393.7785 is affected.

Microsoft Windows 10 Version 1809:

Version 10.0.17763.0 and below 10.0.17763.6893 is affected.

Microsoft Windows 10 Version 21H2:

Version 10.0.19044.0 and below 10.0.19044.5487 is affected.

Microsoft Windows 10 Version 22H2:

Version 10.0.19045.0 and below 10.0.19045.5487 is affected.

Microsoft Windows 11 version 22H2:

Version 10.0.22621.0 and below 10.0.22621.4890 is affected.

Microsoft Windows 11 version 22H3:

Version 10.0.22631.0 and below 10.0.22631.4890 is affected.

Microsoft Windows 11 Version 23H2:

Version 10.0.22631.0 and below 10.0.22631.4890 is affected.

Microsoft Windows 11 Version 24H2:

Version 10.0.26100.0 and below 10.0.26100.3194 is affected.

Microsoft Windows Server 2008 R2 Service Pack 1:

Version 6.1.7601.0 and below 6.1.7601.27566 is affected.

Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation):

Version 6.1.7601.0 and below 6.1.7601.27566 is affected.

Microsoft Windows Server 2008 Service Pack 2:

Version 6.0.6003.0 and below 6.0.6003.23117 is affected.

Microsoft Windows Server 2008 Service Pack 2 (Server Core installation):

Version 6.0.6003.0 and below 6.0.6003.23117 is affected.

Microsoft Windows Server 2012:

Version 6.2.9200.0 and below 6.2.9200.25317 is affected.

Microsoft Windows Server 2012 (Server Core installation):

Version 6.2.9200.0 and below 6.2.9200.25317 is affected.

Microsoft Windows Server 2012 R2:

Version 6.3.9600.0 and below 6.3.9600.22417 is affected.

Microsoft Windows Server 2012 R2 (Server Core installation):

Version 6.3.9600.0 and below 6.3.9600.22417 is affected.

Microsoft Windows Server 2016:

Version 10.0.14393.0 and below 10.0.14393.7785 is affected.

Microsoft Windows Server 2016 (Server Core installation):

Version 10.0.14393.0 and below 10.0.14393.7785 is affected.

Microsoft Windows Server 2019:

Version 10.0.17763.0 and below 10.0.17763.6893 is affected.

Microsoft Windows Server 2019 (Server Core installation):

Version 10.0.17763.0 and below 10.0.17763.6893 is affected.

Microsoft Windows Server 2022:

Version 10.0.20348.0 and below 10.0.20348.3207 is affected.

Microsoft Windows Server 2022, 23H2 Edition (Server Core installation):

Version 10.0.25398.0 and below 10.0.25398.1425 is affected.

Microsoft Windows Server 2025:

Version 10.0.26100.0 and below 10.0.26100.3194 is affected.

Microsoft Windows Server 2025 (Server Core installation):

Version 10.0.26100.0 and below 10.0.26100.3194 is affected.

Exploit Probability

EPSS

8.43%

Percentile

92.21%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.