PT-2025-6336 · Microsoft · Windows Ancillary Function Driver For Winsock+1

Published 2025-02-11 · Updated 2025-07-28 · CVE-2025-21418

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Windows Ancillary Function Driver for WinSock (affected versions not specified)

Description The issue is an elevation-of-privilege vulnerability that allows attackers to gain SYSTEM privileges, giving them full control over a machine. This vulnerability is related to a heap-based buffer overflow in the Windows Ancillary Function Driver for WinSock. The vulnerability has been exploited in the wild, and it is estimated that millions of devices worldwide are threatened. Attackers can exploit this vulnerability by sending specially crafted requests, potentially leading to full system compromise, data destruction, or unauthorized access.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

LPE

Heap Based Buffer Overflow

Weakness Enumeration

CWE-122

Related Identifiers

BDU:2025-01475

CVE-2025-21418

Affected Products

Windows

Windows Ancillary Function Driver For Winsock

References · 76

• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-21418 · Security Note
• https://osv.dev/vulnerability/CVE-2025-21418 · Vendor Advisory
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21418 · Vendor Advisory
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2025-21418 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-01475 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-21418 · Security Note
• https://safe-surf.ru/specialists/bulletins-nkcki/718206 · Security Note
• https://twitter.com/NikitaTarakanov/status/1889791117035544691 · Twitter Post
• https://twitter.com/RedLegg/status/1889702407413641338 · Twitter Post
• https://twitter.com/NickBla41002745/status/1890034469035544835 · Twitter Post
• https://cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21418 · Note
• https://twitter.com/Trej0Jass/status/1889401189693006071 · Twitter Post
• https://twitter.com/Trej0Jass/status/1889401089671537084 · Twitter Post
• https://twitter.com/secured_cyber/status/1889436530764292137 · Twitter Post
• https://twitter.com/achi_tech/status/1889783145114837403 · Twitter Post