CVE-2015-2378
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 · uneditedUntrusted search path vulnerability in Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel Viewer 2007 SP3, and Office Compatibility Pack SP3 allows local users to gain privileges via a Trojan horse DLL in the current working directory, aka "Microsoft Excel DLL Remote Code Execution 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 confidenceDLL hijacking vulnerability in Microsoft Excel where the application loads DLLs from the current working directory without proper validation. An attacker can place a malicious DLL in the same directory as a document opened by Excel, achieving code execution with the user's privileges when Excel loads the Trojan horse DLL.
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= 2007= 2010= 2007all versionsCVSS 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
- Local
- Complexity
- M
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify installed Microsoft Excel versionOpen Excel, go to File > Account > About Excel, or run 'winword.exe /?' from Command Prompt to check version metadata in the executableAffected if Version is 2007 or 2010 (exact builds matter for complete accuracy)
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Identify installed Excel Viewer versionCheck Add/Remove Programs (Programs and Features) for 'Microsoft Excel Viewer' or check the installation directory for ExcelView.exe version metadataAffected if Excel Viewer version 2007 is installed
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Identify installed Office Compatibility Pack versionCheck Add/Remove Programs for 'Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats' and note the versionAffected if Any version of Office Compatibility Pack is installed
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Verify DLL loading behavior from current directoryPlace a test DLL in a folder with an .xlsx file, open that file with Excel, and use Process Monitor (sysinternals) to observe if Excel loads DLLs from that directory pathAffected if Excel loads a DLL from the same directory as the opened document without validation (vulnerable behavior)
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Check for presence of vulnerable DLLs in Excel program directoryExamine the Excel executable's manifest or use Dependency Walker to identify DLLs it attempts to load, particularly those without fully qualified pathsAffected if Excel attempts to load DLLs using relative paths (without full path specification)
Your environment is affected if you have Excel 2007, Excel 2010, Excel Viewer 2007, or any version of Office Compatibility Pack installed, and Excel loads unsigned DLLs from the document's directory.
Generated from the published advisory. Verify against your own configuration.
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 dataApply Microsoft security updates for this vulnerability. Users should avoid opening Excel files from untrusted locations (such as USB drives or download folders) and ensure the current working directory is not writable by untrusted users.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-2378 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2015-2378 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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