dbcve.org
Windows 2003 ServerOperating system · Microsoft

CVE-2011-1991

HIGH · 9.3 CVSS v2.0 Published 2011-09-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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
Multiple untrusted search path vulnerabilities in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allow local users to gain privileges via a Trojan horse DLL in the current working directory, as demonstrated by a directory that contains a .doc, .rtf, or .txt file, related to (1) deskpan.dll in the Display Panning CPL Extension, (2) EAPHost Authenticator Service, (3) Folder Redirection, (4) HyperTerminal, (5) the Japanese Input Method Editor (IME), and (6) Microsoft Management Console (MMC), aka "Windows Components Insecure Library Loading 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

This is an untrusted search path (DLL preloading/hijacking) vulnerability affecting multiple Windows components. When Windows applications load DLLs without specifying a full path, they may search the current working directory first. Attackers can place a malicious DLL (e.g., deskpan.dll) in directories containing common files like .doc, .rtf, or .txt, and trick users into opening those directories, causing the application to load the Trojan horse DLL with elevated privileges.

MitigationApply Microsoft security updates addressing insecure library loading (particularly KB2533623 and KB2567053). Avoid opening files from untrusted or shared network directories, and implement the CWD policy to prevent loading DLLs from the current working directory.

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 2003 ServerOperating system
Affected:all versions
Windows 7Operating system
Affected:all versions
Windows Server 2003Operating system
Affected:all versions
Windows Server 2008Operating system
Affected:all versions= r2
Windows VistaOperating 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
Network
Complexity
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:M/Au:N/C:C/I:C/A:C

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 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' or 'winver' to identify the installed Windows edition and version
    Affected if The version matches any of: Windows XP, Windows Vista, Windows 7, Windows Server 2003, Windows Server 2008, Windows Server 2008 R2 (all versions of these releases)
  2. Verify security updates are installed
    Run 'wmic qfe list' or check 'Control Panel > Programs > View installed updates' for KB2533623 and KB2567053
    Affected if Neither KB2533623 nor KB2567053 is listed among installed updates, meaning the DLL search path fix is absent
  3. Check for suspicious DLLs in document directories
    Search common document folders (.doc, .rtf, .txt locations) for unexpected DLL files, particularly 'deskpan.dll'. Use: 'dir /s /b C:\Users\*.dll' or similar in document directories
    Affected if A DLL file such as deskpan.dll is found in a directory that also contains document files (.doc, .rtf, .txt)
  4. Audit DLL search order behavior
    Check registry key 'HKLM\System\CurrentControlSet\Control\Session Manager\SafeDllSearchMode' - if set to 0, the current working directory is searched before system directories. Run 'reg query "HKLM\System\CurrentControlSet\Control\Session Manager" /v SafeDllSearchMode'
    Affected if SafeDllSearchMode is set to 0 or the key does not exist (default vulnerable state on affected systems), allowing DLL loading from the current working directory

A user is affected if they run any of the listed Windows versions WITHOUT the KB2533623/KB2567053 updates AND have the vulnerable DLL search behavior enabled, making them susceptible to DLL hijacking via malicious DLLs placed alongside document files.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Microsoft security updates addressing insecure library loading (particularly KB2533623 and KB2567053). Avoid opening files from untrusted or shared network directories, and implement the CWD policy to prevent loading DLLs from the current working directory.

Recommended fix Moderate confidence

Windows 10 or Windows 11 (depending on hardware compatibility) or Windows Server 2016/2019/2022 for server environments

  1. 1. Identify all systems running the affected Windows versions (XP, Vista, 2003, 2008, 2008 R2, 7)
  2. 2. Assess each system's eligibility for upgrade to a supported Windows version
  3. 3. For critical systems that cannot be immediately upgraded, apply the Microsoft security update MS11-043 which addresses this specific vulnerability
  4. 4. As a defensive measure, ensure users do not open files from untrusted or shared network locations that could contain malicious DLLs
  5. 5. Implement the Workaround: Set the 'HKLM\System\CurrentControlSet\Control\Session Manager\SafeDLLSearchMode' registry value to 1 to enforce safe DLL search order
  6. 6. After upgrading to a supported Windows version, ensure Windows Update is enabled and configured for automatic security updates
Caveat Legacy applications designed for Windows XP/Vista/2003/2008 may not be compatible with newer Windows versions; some older hardware may not meet requirements for Windows 10/11

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

Fix this in Windows 2003 Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
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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-2011-1991 in production — separate from our analysis above.

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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