CVE-2011-2005: Microsoft Ancillary Function Driver (afd.sys) Improper Input Validation Vulnerability

High severity, CVSS 7.8. Actively exploited: in CISA KEV since 2022-03-28. EPSS: 31.8% chance of exploitation in the next 30 days.

afd.sys in the Ancillary Function Driver in Microsoft Windows XP SP2 and SP3 and Server 2003 SP2 does not properly validate user-mode input passed to kernel mode, which allows local users to gain privileges via a crafted application, aka "Ancillary Function Driver Elevation of Privilege Vulnerability."

Affected products

• Microsoft Windows Server 2003: affected versions not specified
• Microsoft Windows XP: affected versions not specified

Published 2011-10-12. Last modified 2026-06-16.