CVE-2011-2005

Exp

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."

Published: 2011-10-12 Last update: 2026-04-22 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2011-2005 is rated Critical Active Threat (89.2/100): CVSS High severity, with high exploitation likelihood (EPSS 67.09%, 98th percentile). CISA KEV confirms active exploitation (added 2022-03-28) affecting Microsoft / Ancillary Function Driver (afd.sys). Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2011-2005

Name: Microsoft Ancillary Function Driver (afd.sys) Improper Input Validation Vulnerability · CISA KEV detail

Exploit added: 2022-03-28

Action due: 2022-04-18

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2011-2005

EDB-ID Source Kind Published Link
21844 exploit_db edb 2012-10-10 Exploit-DB ↗
18176 exploit_db edb 2011-11-30 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2011-2005

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-28 68.53% 67.09% -1.44%
2 2025-12-27 67.09% 68.53% +1.44%
3 2025-11-03 — 67.09% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2011-2005

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2011-2005

Affected software / configurations for CVE-2011-2005

Vendor Product Version Raw CPE
microsoft windows_server_2003 — cpe:2.3:o:microsoft:windows_server_2003:-:sp2:*:*:*:*:*:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:-:sp2:*:*:professional:*:x64:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:-:sp3:*:*:*:*:*:*

References for CVE-2011-2005

cvelogic Threat Intelligence