dbcve.org
Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 18 Apr 2022.
Windows Server 2003Operating system · Microsoft

CVE-2011-2005

HIGH · 7.8 CVSS v3.1 Published 2011-10-12
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
97/100
Remediation priority · Urgent
In the wild No privileges Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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."

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

afd.sys (Ancillary Function Driver) in Windows XP SP2/SP3 and Server 2003 SP2 fails to properly validate user-mode input before passing it to kernel mode. This allows a local attacker to craft malicious input that escalates privileges from low-privilege user to SYSTEM level by exploiting the kernel-mode driver interface used for Winsock operations.

MitigationApply Microsoft security patches for this vulnerability; for legacy systems no longer supported, consider upgrading to supported Windows versions or implementing application whitelisting to block untrusted applications.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Windows Server 2003Operating system
Affected:all versions
Windows XpOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' from command prompt
    Affected if The system reports Windows XP (any SP) or Windows Server 2003 (any version/SP)
  2. Verify afd.sys driver presence
    Check if C:\Windows\System32\drivers\afd.sys exists using 'dir C:\Windows\System32\drivers\afd.sys'
    Affected if The afd.sys driver file exists on the system (it is present by default on affected Windows versions)
  3. Confirm driver is loaded
    Run 'sc query afd' or check driver list in Device Manager under 'Non-Plug and Play Drivers'
    Affected if The AFD service/driver shows as RUNNING or exists in the driver list
  4. Check if system is patched
    Run 'wmic qfe list' or check Windows Update history for security update KB2295711 (the patch for this CVE)
    Affected if The system is Windows XP or Server 2003 and KB2295711 is NOT installed (system is unpatched)
  5. Verify system is still vulnerable
    Check that the system is XP/Server 2003 AND the afd.sys driver is present AND the security patch KB2295711 is absent
    Affected if All three conditions are true: affected OS, afd.sys present, patch not installed

A system is affected if it runs Windows XP or Windows Server 2003, has the afd.sys driver present, and is missing security update KB2295711.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch docs.microsoft.com →
Interim mitigation

Apply Microsoft security patches for this vulnerability; for legacy systems no longer supported, consider upgrading to supported Windows versions or implementing application whitelisting to block untrusted applications.

Recommended fix High confidence

Windows 7 or later for clients; Windows Server 2008 R2 or later for servers

  1. 1. Assess current systems to identify all Windows XP and Windows Server 2003 machines affected by CVE-2011-2005.
  2. 2. Since Windows XP and Windows Server 2003 are end-of-life and no longer receive security updates, plan migration to a supported Windows version (Windows 7, Windows Server 2008 R2 or later).
  3. 3. Back up all critical data and configurations from affected systems before migration.
  4. 4. Deploy the upgraded operating system on replacement hardware or virtual machines.
  5. 5. Reinstall and reconfigure required applications on the new system.
  6. 6. Migrate user data and verify functionality.
  7. 7. Implement additional controls such as network segmentation to isolate legacy systems if immediate migration is not possible.
Caveat Legacy applications designed for Windows XP/Server 2003 may require updates or replacement; hardware requirements differ for newer OS versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows Server 2003 Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2011-2005 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2011-2005 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data