dbcve.org
ExcelApplication · Microsoft

CVE-2010-3238

HIGH · 9.3 CVSS v2.0 Published 2010-10-13
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
Microsoft Excel 2002 SP3 and 2003 SP3, and Office 2004 for Mac, does not properly validate binary file-format information, which allows remote attackers to execute arbitrary code via a crafted Excel document, aka "Negative Future Function 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

Microsoft Excel 2002 SP3 and 2003 SP3, and Office 2004 for Mac, fail to properly validate binary file-format information when parsing Excel documents. This allows a remote attacker to execute arbitrary code by delivering a specially crafted Excel file that exploits the negative future function parsing flaw.

MitigationApply Microsoft security updates KB2251399 (Excel) and KB2289158 (Office) to address this vulnerability. Additionally, configure Excel's Protected View for files from untrusted sources and educate users to avoid opening attachments from unknown senders.

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= 2003
OfficeApplication
Affected:= 2004

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 Excel version
    Open Microsoft Excel, then go to Help > About Microsoft Excel to view the exact version and service pack. Alternatively, check Add or Remove Programs (Windows) or Applications folder (Mac) for the installed Microsoft Excel version.
    Affected if The version shows Microsoft Excel 2002 (any SP) or Microsoft Excel 2003 (any SP). Note that Office 2004 for Mac is also affected if that version is installed.
  2. Verify Excel security update KB2251399 is installed
    On Windows, open Control Panel > Programs and Features > View installed updates and search for KB2251399. Alternatively, check the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates for entry with KB2251399.
    Affected if KB2251399 is NOT listed among installed updates, meaning the vulnerability remains unpatched.
  3. Verify Office security update KB2289158 is installed (for Office 2004 for Mac)
    On Windows, open Control Panel > Programs and Features > View installed updates and search for KB2289158. On Mac, check System Preferences > Software Update or review installed Microsoft Office updates.
    Affected if KB2289158 is NOT listed among installed updates, leaving the vulnerability unpatched.
  4. Confirm Excel file parsing is accessible
    This vulnerability is triggered when Excel parses specially crafted binary Excel files. Verify whether users in your environment have the ability to open Excel file attachments or download Excel files from external sources.
    Affected if Users can open Excel files from untrusted or unknown sources without restrictions, which would allow exploitation of this parsing flaw.

A user is affected if they have Excel 2002, Excel 2003, or Office 2004 for Mac installed AND neither security update KB2251399 (for Excel) nor KB2289158 (for Office) has been 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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Microsoft security updates KB2251399 (Excel) and KB2289158 (Office) to address this vulnerability. Additionally, configure Excel's Protected View for files from untrusted sources and educate users to avoid opening attachments from unknown senders.

Recommended fix Moderate confidence

Upgrade to a currently supported Microsoft Office version (e.g., Microsoft 365, Office 2021, or at minimum Office 2010 or later)

  1. 1. Obtain a supported version of Microsoft Office (Excel) from official Microsoft channels
  2. 2. Uninstall the affected versions: Excel 2002 SP3, Excel 2003 SP3, or Office 2004 for Mac
  3. 3. Install the latest supported version of Microsoft Office that includes Excel
  4. 4. Verify the installation by opening Excel and confirming the version number
  5. 5. Ensure Windows Update or Microsoft Update is enabled to receive future security updates
Caveat Legacy file formats from Excel 2002/2003 may have compatibility considerations; macro settings and add-ins may need reconfiguration in newer versions

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

Fix this in Excel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.

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-2010-3238 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