All vulnerabilities
CVE-2025-21418

Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability

Microsoft WindowsOperating systems
Open in ThreatlineRecord JSON
CVSS
7.8High
ExploitationExploited in the wildAdded to KEV 11 Feb 2025CISA KEV
Exploit odds (EPSS)1.57%Chance of exploitation activity in the next 30 days, higher than 75% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in10.0.10240.20915Also 10.0.14393.7785, 10.0.17763.6893 and 11 moreCVE List
Federal deadline4 Mar 2025Remediation due date for US federal agenciesCISA KEV
CISA required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. CISA KEV

What fixes it

  • 10.0.10240.20915Windows 10 Version 1507CVE List
  • 10.0.14393.7785Windows 10 Version 1607CVE List
  • 10.0.17763.6893Windows 10 Version 1809CVE List
  • 10.0.19044.5487Windows 10 Version 21H2CVE List
  • 10.0.19045.5487Windows 10 Version 22H2CVE List
  • 10.0.22621.4890Windows 11 version 22H2CVE List
Show all 25 fixed versions
  • 10.0.22631.4890Windows 11 version 22H3CVE List
  • 10.0.22631.4890Windows 11 Version 23H2CVE List
  • 10.0.26100.3194Windows 11 Version 24H2CVE List
  • 6.1.7601.27566Windows Server 2008 R2 Service Pack 1CVE List
  • 6.1.7601.27566Windows Server 2008 R2 Service Pack 1 (Server Core installation)CVE List
  • 6.0.6003.23117Windows Server 2008 Service Pack 2CVE List
  • 6.0.6003.23117Windows Server 2008 Service Pack 2 (Server Core installation)CVE List
  • 6.2.9200.25317Windows Server 2012CVE List
  • 6.2.9200.25317Windows Server 2012 (Server Core installation)CVE List
  • 6.3.9600.22417Windows Server 2012 R2CVE List
  • 6.3.9600.22417Windows Server 2012 R2 (Server Core installation)CVE List
  • 10.0.14393.7785Windows Server 2016CVE List
  • 10.0.14393.7785Windows Server 2016 (Server Core installation)CVE List
  • 10.0.17763.6893Windows Server 2019CVE List
  • 10.0.17763.6893Windows Server 2019 (Server Core installation)CVE List
  • 10.0.20348.3207Windows Server 2022CVE List
  • 10.0.25398.1425Windows Server 2022, 23H2 Edition (Server Core installation)CVE List
  • 10.0.26100.3194Windows Server 2025CVE List
  • 10.0.26100.3194Windows Server 2025 (Server Core installation)CVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 11 Feb 2025Added to CISA KEVCISA KEV
  2. 11 Feb 2025, 17:58 UTCPublishedCVE List

Description

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.

Text from CVE List

Affected versions 25

  • Windows 10 Version 1507affected: 10.0.10240.0 before 10.0.10240.20915CVE List
  • Windows 10 Version 1607affected: 10.0.14393.0 before 10.0.14393.7785CVE List
  • Windows 10 Version 1809affected: 10.0.17763.0 before 10.0.17763.6893CVE List
  • Windows 10 Version 21H2affected: 10.0.19044.0 before 10.0.19044.5487CVE List
  • Windows 10 Version 22H2affected: 10.0.19045.0 before 10.0.19045.5487CVE List
  • Windows 11 version 22H2affected: 10.0.22621.0 before 10.0.22621.4890CVE List
  • Windows 11 version 22H3affected: 10.0.22631.0 before 10.0.22631.4890CVE List
  • Windows 11 Version 23H2affected: 10.0.22631.0 before 10.0.22631.4890CVE List
  • Windows 11 Version 24H2affected: 10.0.26100.0 before 10.0.26100.3194CVE List
  • Windows Server 2008 R2 Service Pack 1affected: 6.1.7601.0 before 6.1.7601.27566CVE List
  • Windows Server 2008 R2 Service Pack 1 (Server Core installation)affected: 6.1.7601.0 before 6.1.7601.27566CVE List
  • Windows Server 2008 Service Pack 2affected: 6.0.6003.0 before 6.0.6003.23117CVE List
  • Windows Server 2008 Service Pack 2 (Server Core installation)affected: 6.0.6003.0 before 6.0.6003.23117CVE List
  • Windows Server 2012affected: 6.2.9200.0 before 6.2.9200.25317CVE List
  • Windows Server 2012 (Server Core installation)affected: 6.2.9200.0 before 6.2.9200.25317CVE List
  • Windows Server 2012 R2affected: 6.3.9600.0 before 6.3.9600.22417CVE List
  • Windows Server 2012 R2 (Server Core installation)affected: 6.3.9600.0 before 6.3.9600.22417CVE List
  • Windows Server 2016affected: 10.0.14393.0 before 10.0.14393.7785CVE List
  • Windows Server 2016 (Server Core installation)affected: 10.0.14393.0 before 10.0.14393.7785CVE List
  • Windows Server 2019affected: 10.0.17763.0 before 10.0.17763.6893CVE List
  • Windows Server 2019 (Server Core installation)affected: 10.0.17763.0 before 10.0.17763.6893CVE List
  • Windows Server 2022affected: 10.0.20348.0 before 10.0.20348.3207CVE List
  • Windows Server 2022, 23H2 Edition (Server Core installation)affected: 10.0.25398.0 before 10.0.25398.1425CVE List
  • Windows Server 2025affected: 10.0.26100.0 before 10.0.26100.3194CVE List
  • Windows Server 2025 (Server Core installation)affected: 10.0.26100.0 before 10.0.26100.3194CVE List

References 3