dbcve.org
Windows 2003 ServerOperating system · Microsoft

CVE-2011-1268

HIGH · 10.0 CVSS v2.0 Published 2011-06-16
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
The SMB client 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 remote SMB servers to execute arbitrary code via a crafted (1) SMBv1 or (2) SMBv2 response, aka "SMB Response Parsing 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

A vulnerability in the SMB client implementation in Microsoft Windows allows a remote malicious SMB server to send specially crafted SMBv1 or SMBv2 responses that can trigger a buffer overflow, leading to arbitrary code execution on the vulnerable client system.

MitigationApply Microsoft security updates MS11-019 and MS11-020, disable SMBv1 via registry if not needed, and block inbound SMB traffic (ports 445/139) at network perimeter firewalls.

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
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/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 Windows version
    Run 'winver' or 'systeminfo' from command prompt to determine the exact Windows version and build number
    Affected if The version is Windows XP, Windows Vista, Windows 7, Windows Server 2003, Windows Server 2008, or Windows Server 2008 R2
  2. Verify SMB client is enabled
    Check registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Start and ensure it is set to 2 (Automatic) or 3 (Manual), or verify the 'Computer Browser' and 'LanmanWorkstation' services are not disabled
    Affected if SMB client services are running or set to start automatically, enabling the system to act as an SMB client and receive responses from remote servers
  3. Confirm SMBv1 client is active
    Check registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\mrxdav for the value 'Start' (2 = disabled, 3 = manual, 4 = automatic), or run 'sc query mrxdav' to check service status
    Affected if The mrxdav (WebDAV Redirector) service is enabled, which loads SMBv1 client functionality and makes the vulnerability exploitable
  4. Verify SMBv2 client is active
    Check registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Smb2 for the 'Start' value, or verify the 'Smb2' service exists and is not disabled
    Affected if SMBv2 client support is enabled, as both SMBv1 and SMBv2 client implementations contain the buffer overflow flaw
  5. Check network exposure to SMB
    Run 'netstat -an | findstr :445' or check if inbound connections on TCP port 445 are allowed through any installed firewall
    Affected if The system can receive inbound SMB connections, which could allow a remote attacker to deliver the malicious SMB response

A system is affected if it runs any of the listed Windows versions with SMB client services (SMBv1 or SMBv2) enabled and has network accessibility that could allow a remote SMB server to send crafted responses.

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 MS11-019 and MS11-020, disable SMBv1 via registry if not needed, and block inbound SMB traffic (ports 445/139) at network perimeter firewalls.

Recommended fix High confidence
  1. Locate and apply the Microsoft security update associated with CVE-2011-1268 (refer to Microsoft Security Bulletin MS11-019 and MS11-020 from April 2011)
  2. For Windows XP SP2/SP3: Install the applicable update from Windows Update or the Microsoft Download Center
  3. For Windows Server 2003 SP2: Install the applicable update from Windows Update or the Microsoft Download Center
  4. For Windows Vista SP1/SP2: Install the applicable update via Windows Update
  5. For Windows Server 2008 Gold/SP2/R2: Install the applicable update via Windows Update
  6. For Windows 7 Gold/SP1: Install the applicable update via Windows Update
  7. After applying the patch, restart the affected systems to complete the remediation
  8. Verify the patch was successfully installed by checking the installed updates list

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
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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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-2011-1268 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