CVE-2011-1237
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 · uneditedUse-after-free vulnerability in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows local users to gain privileges via a crafted application that leverages incorrect driver object management, a different vulnerability than other "Vulnerability Type 1" CVEs listed in MS11-034, aka "Win32k Use After Free 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 confidenceUse-after-free vulnerability in win32k.sys (Windows Kernel-Mode Driver) allows local authenticated users to gain elevated privileges via a crafted application that triggers incorrect driver object management, leading to memory corruption.
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 dataall versionsall versionsall versionsall versions= r2all versionsall versionsCVSS 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
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/AC:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify Windows versionRun 'systeminfo' or 'winver' to get the exact Windows version and build numberAffected if The version is Windows XP, Vista, 7, Server 2003, Server 2008, or Server 2008 R2 (any edition)
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Locate win32k.sys driver fileCheck C:\Windows\System32\win32k.sys and view its Properties > Details to see the File VersionAffected if The driver file exists (present on all affected Windows versions by default)
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Compare driver version to vulnerable releasesCross-reference the win32k.sys file version against known build numbers prior to the MS11-034 patch for your specific Windows versionAffected if The win32k.sys version is older than the patched build for your Windows version without MS11-034 applied
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Check for MS11-034 security updateRun 'wmic qfe list | findstr /i "KB"' or view 'Installed Updates' in Control Panel to verify if KBxxxx (MS11-034) is installedAffected if The MS11-034 update is NOT installed on the system
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Verify exploitability contextConfirm the system allows local user authentication (terminal services, RDP, or console login) - the flaw requires a local authenticated user to execute the crafted applicationAffected if Local user access exists and the unpatched win32k.sys is in use
A system is affected if it runs an unpatched Windows version from XP through Server 2008 R2 and lacks the MS11-034 update, allowing a local authenticated user to trigger the win32k.sys use-after-free for privilege escalation.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataDeploy Microsoft security updates from MS11-034 or subsequent Windows updates that address this kernel-mode driver vulnerability; this is a patch deployment rather than code-level fix.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-1237 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2011-1237 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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