CVEs / CVE-2011-2005

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

Known exploited in the CISA KEV catalog since 28 Mar 2022
high 7.8 CVSS 3.1 (NVD)
EPSS 31.7% chance of exploitation in the next 30 days, higher than 98% of CVEs (30 Oct 2026)
Last changed at its sources 16 Jun 2026

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Summary

afd.sys in the Ancillary Function Driver in Microsoft Windows does not properly validate user-mode input passed to kernel mode, which allows local users to gain privileges via a crafted application.
CISA, Known Exploited Vulnerabilities catalog

Description

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."
The CVE record, via NVD · published 12 Oct 2011 · NVD status: Analyzed

Affected and fixed versions

As stated by the CVE record (from the CNA)
Product	Affected	Fixed in
n/a n/a	n/a	—

Exploitation

In CISA KEV since	28 Mar 2022
Due date for US federal agencies	18 Apr 2022
Used in ransomware campaigns	Unknown
Required action	Apply updates per vendor instructions.

Severity

CVSS 3.1	7.8 high `CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H` Scored by NVD

References

CVE-2011-2005 on NVD
CVE-2011-2005 in the CISA KEV catalog
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-080 Patch, Vendor Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A13114 Broken Link
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2011-2005 US Government Resource

Sources

Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.

This product uses data from the NVD API but is not endorsed or certified by the NVD.