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Windows 2003 ServerOperating system · Microsoft

CVE-2011-1281

HIGH · 7.2 CVSS v2.0 Published 2011-07-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
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
The Client/Server Run-time Subsystem (aka CSRSS) in the Win32 subsystem 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 does not properly restrict the number of console objects for a process, which allows local users to gain privileges or cause a denial of service (memory corruption) via a crafted application that triggers an incorrect memory assignment for a user transaction, aka "CSRSS Local EOP AllocConsole 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 · moderate confidence

This is a local privilege escalation vulnerability in the Windows Client/Server Run-time Subsystem (CSRSS). The CSRSS fails to properly restrict the number of console objects for a process, allowing a crafted application to trigger incorrect memory assignment during user transactions, leading to memory corruption that can be exploited for privilege escalation or DoS.

MitigationApply the Microsoft security update for CVE-2011-1281 to all affected Windows systems. For systems that cannot be patched, consider restricting local user access and monitoring for indicators of compromise involving console allocation operations.

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
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 checks

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

  1. Identify the Windows version and edition
    Run 'winver' or 'systeminfo' from command prompt and note the Windows version and build number
    Affected if The version is Windows XP, Vista, Windows 7, Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2 (all versions of these are affected)
  2. Verify if security update MS11-027 is installed
    Run 'wmic qfe list' or check Windows Update history for security update KB2507938 (the patch for CVE-2011-1281)
    Affected if The security update is NOT installed and the Windows version matches an affected product from step 1
  3. Confirm CSRSS service is running
    Open Task Manager, go to Services tab, locate 'CSRSS' service and verify its status is Running, or run 'sc query csrss' from command prompt
    Affected if CSRSS service is not running (system instability) or shows unusual status
  4. Check for event log indicators of console allocation issues
    Open Event Viewer, navigate to Windows Logs > Application and System, filter for events related to CSRSS failures, console errors, or memory allocation failures around the time of any suspected exploitation
    Affected if There are unexplained CSRSS-related error events or console allocation failures on the system

The system is potentially affected if it runs an unpatched Windows version from the affected list (XP, Vista, 7, Server 2003, Server 2008, Server 2008 R2) and security update KB2507938 is not installed.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Microsoft security update for CVE-2011-1281 to all affected Windows systems. For systems that cannot be patched, consider restricting local user access and monitoring for indicators of compromise involving console allocation operations.

Fix this in Windows 2003 Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

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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-2011-1281 in production — separate from our analysis above.

No notes yet

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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