CVE-2009-2496
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 · uneditedHeap-based buffer overflow in the Office Web Components ActiveX Control in Microsoft Office XP SP3, Office 2003 SP3, Office XP Web Components SP3, Office 2003 Web Components SP3, Office 2003 Web Components SP1 for the 2007 Microsoft Office System, Internet Security and Acceleration (ISA) Server 2004 SP3 and 2006 SP1, and Office Small Business Accounting 2006 allows remote attackers to execute arbitrary code via unspecified parameters to unknown methods, aka "Office Web Components Heap Corruption 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 confidenceHeap-based buffer overflow in the Office Web Components ActiveX Control allows remote attackers to execute arbitrary code via unspecified parameters to unknown methods. This is a client-side ActiveX vulnerability affecting multiple Microsoft Office versions and related products, enabling remote code execution when users interact with malicious content.
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= 2002= 2004= 2006all versions= 2003= xp= 2000= 2003= xp= 2003CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check if Office Web Components ActiveX control is installedOpen Windows Registry and look for the Office Web Components CLSID under HKEY_CLASSES_ROOT\CLSID. The primary CLSID is {0002E511-0000-0000-C000-000000000046}. Check if this key exists.Affected if The CLSID key exists in the registry, indicating the ActiveX control is installed.
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Verify Internet Explorer ActiveX enabled for Office Web ComponentsCheck registry value under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Ext\PreApproved for the Office Web Components CLSID. If present, the control is allowed to run in Internet Explorer.Affected if The Office Web Components CLSID appears in the PreApproved list, meaning ActiveX controls from this component can run in IE.
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Check installed Microsoft Office versionOpen Registry editor and check HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\version\Common\InstallRoot, or run 'winver' command, or check Add/Remove Programs for Microsoft Office entries.Affected if Any version of Microsoft Office is installed.
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Check Office Web Components standalone installationLook in Add/Remove Programs for 'Microsoft Office Web Components' or check registry under HKLM\SOFTWARE\Microsoft\Office\OWC for version information.Affected if Office Web Components is installed as a standalone component.
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Check for security patch installationVerify if Microsoft security update for CVE-2009-2496 (MS09-043) is installed by checking Windows Update history or by looking for the presence of updated OWC files with version timestamps after August 2009.Affected if The security patch for CVE-2009-2496 is NOT installed.
A user is affected if the Office Web Components ActiveX control is installed, ActiveX is enabled in Internet Explorer, and the CVE-2009-2496 security patch has not been applied.
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.
dbcve · scopedApply Microsoft security patches for CVE-2009-2496, disable the vulnerable ActiveX control via kill bit, or disable ActiveX in Internet Explorer as a defense-in-depth measure.
Upgrade to Microsoft Office 2007 Service Pack 2 or later, or migrate to current supported Office versions (Microsoft 365 Apps)
- Apply Microsoft Security Bulletin MS09-043 which addresses this vulnerability. Download the appropriate security update for your specific product version from Microsoft Update or the Microsoft Download Center.
- For Office XP SP3: Install security update 957507
- For Office 2003 SP3: Install security update 957508
- For Office XP Web Components SP3: Install security update 957509
- For Office 2003 Web Components SP3: Install security update 957509
- For ISA Server 2004 SP3: Install security update 957509
- For ISA Server 2006 SP1: Install security update 957509
- Alternatively, disable the Office Web Components ActiveX control in Internet Explorer via Internet Options > Security > Custom Level > ActiveX controls and plugins > Disable 'Initialize and script ActiveX controls not marked as safe'
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,880.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-2496 — 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-2009-2496 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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- 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