Windows systems: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability (CVE-2025-21418) #shorts

Summary

Today, we delve into the critical CVE-2025-21418, a vulnerability that affects multiple versions and editions of Microsoft Windows, including Windows 10, Windows 11, and several server versions. Published in February 2025, CVE-2025-21418 presents a significant security concern for users worldwide due to its nature as a heap-based buffer overflow in the Windows Ancillary Function Driver for WinSock.

Product details

CVE-2025-21418 targets Microsoft operating systems, impacting Windows 10 versions from 1507 to 22H2, Windows 11 versions from 22H2 to 24H2, as well as Windows Server editions from 2008 through to the upcoming Server 2025. This extensive range of affected products necessitates urgent attention from system administrators and users to safeguard their systems.

Vulnerability type summary

The vulnerability, classified under CWE-122, is a heap-based buffer overflow. Such vulnerabilities occur when data exceeds the storage boundary of a given buffer, potentially allowing attackers to execute arbitrary code or cause a denial of service. This is particularly concerning given that buffer overflows remain a common vector for cyber attacks.

Details of the vulnerability

CVE-2025-21418 is identified as an elevation of privilege vulnerability in the Windows Ancillary Function Driver for WinSock. This vulnerability can potentially grant attackers heightened privileges on a vulnerable system, posing risks of unauthorized access and system manipulation. Microsoft addressed this vulnerability in its February 2025 Patch Tuesday, which included fixes for numerous security issues. Users are advised to update their systems promptly to mitigate the risk of exploitation.

Conclusion

With the release of the February 2025 security patches, Microsoft has addressed numerous vulnerabilities, including the severe CVE-2025-21418. This buffer overflow issue highlights the persistent threat of privilege escalation attacks. It's imperative for all users and administrators of affected Windows versions to apply the latest security updates to protect their systems and data from potential threats.

Watch the full video on YouTube: CVE-2025-21418

Remediation and exploitation details

This chain involves the following actors

This following systems are involved

Attack entry point

Remediation actions

Exploitation actions

Related Content

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CVE database technical details

CVE ID
CVE-2025-21418
Description
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Provider
microsoft
CWE / problem types
CWE-122: Heap-based Buffer Overflow
Affected Software Versions
Microsoft:Windows 10 Version 1809:[{'version': '10.0.17763.0', 'lessThan': '10.0.17763.6893', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2019:[{'version': '10.0.17763.0', 'lessThan': '10.0.17763.6893', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2019 (Server Core installation):[{'version': '10.0.17763.0', 'lessThan': '10.0.17763.6893', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2022:[{'version': '10.0.20348.0', 'lessThan': '10.0.20348.3207', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 10 Version 21H2:[{'version': '10.0.19043.0', 'lessThan': '10.0.19044.5487', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 11 version 22H2:[{'version': '10.0.22621.0', 'lessThan': '10.0.22621.4890', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 10 Version 22H2:[{'version': '10.0.19045.0', 'lessThan': '10.0.19045.5487', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2025 (Server Core installation):[{'version': '10.0.26100.0', 'lessThan': '10.0.26100.3194', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 11 version 22H3:[{'version': '10.0.22631.0', 'lessThan': '10.0.22631.4890', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 11 Version 23H2:[{'version': '10.0.22631.0', 'lessThan': '10.0.22631.4890', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2022, 23H2 Edition (Server Core installation):[{'version': '10.0.25398.0', 'lessThan': '10.0.25398.1425', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 11 Version 24H2:[{'version': '10.0.26100.0', 'lessThan': '10.0.26100.3194', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2025:[{'version': '10.0.26100.0', 'lessThan': '10.0.26100.3194', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 10 Version 1507:[{'version': '10.0.10240.0', 'lessThan': '10.0.10240.20915', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows 10 Version 1607:[{'version': '10.0.14393.0', 'lessThan': '10.0.14393.7785', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2016:[{'version': '10.0.14393.0', 'lessThan': '10.0.14393.7785', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2016 (Server Core installation):[{'version': '10.0.14393.0', 'lessThan': '10.0.14393.7785', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2008 Service Pack 2:[{'version': '6.0.6003.0', 'lessThan': '6.0.6003.23117', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2008 Service Pack 2 (Server Core installation):[{'version': '6.0.6003.0', 'lessThan': '6.0.6003.23117', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2008 Service Pack 2:[{'version': '6.0.6003.0', 'lessThan': '6.0.6003.23117', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2008 R2 Service Pack 1:[{'version': '6.1.7601.0', 'lessThan': '6.1.7601.27566', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2008 R2 Service Pack 1 (Server Core installation):[{'version': '6.1.7601.0', 'lessThan': '6.1.7601.27566', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2012:[{'version': '6.2.9200.0', 'lessThan': '6.2.9200.25317', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2012 (Server Core installation):[{'version': '6.2.9200.0', 'lessThan': '6.2.9200.25317', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2012 R2:[{'version': '6.3.9600.0', 'lessThan': '6.3.9600.22417', 'versionType': 'custom', 'status': 'affected'}],Microsoft:Windows Server 2012 R2 (Server Core installation):[{'version': '6.3.9600.0', 'lessThan': '6.3.9600.22417', 'versionType': 'custom', 'status': 'affected'}]
Date Published
2025-02-11T17:58:17.776Z
Last Updated
2025-03-12T01:42:16.507Z