dbcve.org
ExcelApplication · Microsoft

CVE-2011-0105

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
High EPSS 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
Microsoft Excel 2002 SP3, Office 2004 and 2008 for Mac, and Open XML File Format Converter for Mac obtain a certain length value from an uninitialized memory location, which allows remote attackers to trigger a buffer overflow and execute arbitrary code via a crafted Excel file, aka "Excel Data Initialization 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

This vulnerability in Microsoft Excel 2002 SP3, Office 2004/2008 for Mac, and Open XML File Format Converter for Mac stems from the software reading a length value from uninitialized memory. This improper memory handling allows attackers to trigger a buffer overflow by providing a crafted Excel file, potentially leading to arbitrary code execution on the targeted system.

MitigationOrganizations should prioritize deploying the Microsoft security patch for this vulnerability and implement controls to prevent opening untrusted Excel files from unknown or unverified sources until patches are applied.

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:= 2002
OfficeApplication
Affected:= 2004= 2008
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. Check installed Microsoft Excel version on Windows
    Open Excel, go to Help > About Microsoft Excel to see the exact version, or check Programs and Features in Control Panel
    Affected if Version is 2002 or any later version without the MS11-021 security patch applied
  2. Check installed Microsoft Office version on Mac
    Open any Office application, go to the application menu and select About Microsoft Office, or check the Applications folder for the Microsoft Office version
    Affected if Version is Office 2004, Office 2008, or any later version without the security patch applied
  3. Check if Open XML File Format Converter for Mac is installed
    Search the Applications folder or use Spotlight to locate 'Open XML File Format Converter'
    Affected if The converter is present on the system (all versions are affected)
  4. Verify if Excel file handling is enabled or actively used
    Check if .xlsx or .xls file extensions are associated with Microsoft Excel, or review recent Excel file access in the system
    Affected if Excel is installed and can be used to open Excel files, which is the attack vector for this vulnerability

The environment is affected if Microsoft Excel 2002 or later, Office 2004/2008 for Mac, or Open XML File Format Converter for Mac is installed without the MS11-021 patch, and the system can open Excel files.

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

Organizations should prioritize deploying the Microsoft security patch for this vulnerability and implement controls to prevent opening untrusted Excel files from unknown or unverified sources until patches are applied.

Recommended fix High confidence

Office 2011 for Mac or later (for Mac products); Excel 2002 with MS11-021 applied (KB2490387); or migrate to Microsoft 365/Office 365 subscription for continuous security updates

  1. Obtain and install the appropriate Microsoft security update for your version: MS11-021 (KB2490387) for Excel 2002, or download and install newer versions of Microsoft Office for Mac that include security fixes
  2. For Excel 2002 SP3: Apply security update MS11-021 from Microsoft Update or download center
  3. For Office 2004 for Mac and Office 2008 for Mac: Upgrade to Office 2011 for Mac or later, which contains the security fix
  4. For Open XML File Format Converter for Mac: Upgrade to a newer version or replace with the built-in file conversion in Office 2011 or later for Mac
  5. After applying updates or upgrading, verify the software version matches the fixed release
Caveat Office 2011 for Mac may have compatibility differences with older file formats; Microsoft 365 requires subscription; older Mac OS versions may not support newer Office releases

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Excel 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-2011-0105 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