CVE-2011-1232
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 · uneditedwin32k.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 triggers a NULL pointer dereference, a different vulnerability than other "Vulnerability Type 2" CVEs listed in MS11-034, aka "Win32k Null Pointer De-reference 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 confidenceThis is a local privilege escalation vulnerability in the Windows kernel-mode driver (win32k.sys). A local authenticated attacker can execute a specially crafted application that triggers a NULL pointer dereference in win32k.sys, allowing elevation from low-privileged user account to SYSTEM-level privileges. The vulnerability affects multiple Windows versions from XP through 7 and Server 2003 through 2008 R2.
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 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to determine the installed Windows edition and version.Affected if The system runs Windows XP, Vista, 7, Server 2003, Server 2008, or Server 2008 R2.
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Verify win32k.sys file versionLocate win32k.sys in the System32 folder (e.g., C:\Windows\System32\win32k.sys), right-click and view Properties, or run 'wmic datafile where "name='C:\\Windows\\System32\\win32k.sys'" get Version,FileSize' to retrieve the file version.Affected if The win32k.sys version corresponds to an unpatched build for the detected Windows version.
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Check if MS11-034 update is installedRun 'wmic qfe list' or 'Get-HotFix | Where-Object {$_.HotFixID -eq "KB956802"}' in PowerShell to list installed Windows updates.Affected if The security update KB956802 (MS11-034) is NOT listed among installed hotfixes.
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Confirm user context for exploitationVerify that low-privileged user accounts exist on the system using 'net user' or by checking Local Users and Groups (lusrmgr.msc).Affected if Low-privileged (non-administrator) user accounts are present on the system.
A system is affected if it runs an unpatched Windows version from XP through Server 2008 R2 and the MS11-034 (KB956802) update is missing, allowing any local user account to potentially escalate to SYSTEM privileges through win32k.sys.
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 dataApply Microsoft security update MS11-034 which patches this vulnerability in win32k.sys. For end-of-life systems that cannot be patched, implement compensating controls such as restricting local user permissions, application whitelening, and enhanced monitoring for suspicious processes.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-1232 — 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-2011-1232 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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- 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
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