ExcelApplication · Microsoft

CVE-2012-1887

HIGH · 9.3 CVSS v2.0 Published 2012-11-14
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
Use-after-free vulnerability in Microsoft Excel 2003 SP3, 2007 SP2 and SP3, and 2010 SP1, and Office 2008 and 2011 for Mac, allows remote attackers to execute arbitrary code via a crafted spreadsheet, aka "Excel SST Invalid Length Use After Free 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

Use-after-free vulnerability in Microsoft Excel and Office for Mac that occurs during parsing of SST (Shared String Table) records in spreadsheet files. When processing a crafted spreadsheet with an invalid SST length, the application frees memory but later attempts to access that freed memory region, allowing arbitrary code execution.

MitigationApply Microsoft security updates (MS12-076) to patch affected Excel and Office installations; until patched, avoid opening spreadsheets from untrusted sources and disable macro execution.

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:= 2003= 2007= 2010
OfficeApplication
Affected:= 2008= 2011

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 Microsoft Excel version on Windows
    Open Excel, go to File > Account > About Excel, or run 'winword.exe /?' from command line, or check Add/Remove Programs for the installed version
    Affected if Version is 2003, 2007, or 2010
  2. Identify Microsoft Office version on Mac
    Open any Office application, go to Excel/Word/PowerPoint menu > About Microsoft Excel/Word/PowerPoint, or check Applications folder for version info
    Affected if Version is 2008 or 2011 (for Mac)
  3. Check if security update MS12-076 has been applied
    On Windows, open Control Panel > Programs and Features > View installed updates and search for KB2726927 (Excel 2010), KB2687323 (Excel 2007), or KB2597086 (Excel 2003); on Mac, check for recent Office updates via Help > Check for Updates
    Affected if The specific KB update for the installed version is NOT installed (meaning the system is still vulnerable)
  4. Verify Excel file parsing functionality is active
    Confirm Excel application can open .xls or .xlsx files - the vulnerability triggers during SST (Shared String Table) record parsing when opening spreadsheet files
    Affected if Excel can open spreadsheet files and the version is unpatched (vulnerable versions listed above without corresponding KB update)

A user is affected if they are running Excel 2003, 2007, or 2010 on Windows or Office 2008/2011 on Mac AND the MS12-076 security update has not been applied, making them vulnerable when opening crafted spreadsheet files with invalid SST length.

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 (MS12-076) to patch affected Excel and Office installations; until patched, avoid opening spreadsheets from untrusted sources and disable macro execution.

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

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2012-1887 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2012-1887 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