dbcve.org
ExcelApplication · Microsoft

CVE-2011-0097

HIGH · 9.3 CVSS v2.0 Published 2011-04-13
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
Integer underflow in Microsoft Excel 2002 SP3, 2003 SP3, 2007 SP2, and 2010; Office 2004 and 2008 for Mac; Open XML File Format Converter for Mac; Excel Viewer SP2; and Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP2 allows remote attackers to execute arbitrary code via a crafted 400h substream in an Excel file, which triggers a stack-based buffer overflow, aka "Excel Integer Overrun 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

Integer underflow in Microsoft Excel parsing a crafted 400h substream within malicious .xls files causes a stack-based buffer overflow, enabling remote arbitrary code execution. The vulnerability affects Excel 2002-2010, Office for Mac 2004/2008, and related compatibility products.

MitigationApply Microsoft security updates (MS11-009) to all affected Office installations. Until patched, warn users not to open untrusted Excel attachments and consider blocking .xls files from external sources at the email gateway.

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
ExcelApplication
Affected:all versions= 2002= 2003= 2007= 2010
Excel ViewerApplication
Affected:all versions
OfficeApplication
Affected:= 2004= 2008
Office Compatibility PackApplication
Affected:= 2007
Open Xml File Format ConverterApplication
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. Identify installed Microsoft Office and Excel products
    Open Control Panel > Programs and Features, or run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion' via PowerShell to list installed Microsoft Office components
    Affected if Any Microsoft Excel, Office, Excel Viewer, Office Compatibility Pack, or Open Xml File Format Converter version is installed and matches the affected range (Excel 2002-2010, Office 2004/2008, Excel Viewer all versions, Compatibility Pack 2007, Converter all versions)
  2. Verify if MS11-009 security update is installed
    Run 'Get-HotFix -Id KB2490380' in PowerShell or check Windows Update history for security update KB2490380, which patches CVE-2011-0097
    Affected if The KB2490380 update is NOT installed on the system - this means the vulnerability is present
  3. Confirm Excel file parsing is accessible
    Verify that Microsoft Excel or Excel Viewer executable exists on the system at typical paths such as C:\Program Files\Microsoft Office\Office14\EXCEL.EXE or C:\Program Files (x86)\Microsoft Office\Office12\EXCEL.EXE
    Affected if Excel executables are present and can be used to open .xls files, enabling the attack vector
  4. Check for disabled Office file blocking
    Inspect Group Policy settings under Computer Configuration > Administrative Templates > Microsoft Office > File Validation or check registry key HKCU\Software\Microsoft\Office\14.0\Excel\Security\FileValidation for value 0 (disabled)
    Affected if File validation is disabled or not enforced, allowing potentially malicious .xls files to be opened without warning

The environment is affected if any of the listed vulnerable Microsoft Excel, Office, or related products are installed AND the MS11-009 (KB2490380) security update has not been applied.

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 Microsoft security updates (MS11-009) to all affected Office installations. Until patched, warn users not to open untrusted Excel attachments and consider blocking .xls files from external sources at the email gateway.

Fix this in Excel Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2011-0097 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