CVE-2009-0561Office Vulnerability
Integer overflow in Excel in Microsoft Office 2000 SP3, Office XP SP3, Office 2003 SP3, and Office 2004 and 2008 for Mac; Excel in 2007 Microsoft Office System SP1 and SP2; Open XML File Format Converter for Mac; Microsoft Office Excel Viewer 2003 SP3; Microsoft Office Excel…
Published Jun 10, 2009 · Updated Apr 22, 2026
Key Facts
Patch immediately- CVE-2009-0561 is a critical-severity vulnerability (CVSS 9.3 v2) affecting Office (Microsoft), Office Compatibility Pack For Word Excel Ppt 2007 (Microsoft), Office Excel (Microsoft) and 3 more products.
- It is exploited in the wild, listed in Industry KEV feed since Oct 18, 2012. No public exploit code is known.
- EPSS estimates a 37% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v2
9.3
AV:N/AC:M/Au:N/C:C/I:C/A:C
EPSS (30-day exploit likelihood)
37%
Higher than 98.5% of all scored CVEs
Exploit maturity
Exploited (KEV)
ATLAS score
54/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Oct 18, 2012
1226 days after publication
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Exploited (KEV)
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
1
Reports of active use
Advisories And Exploit References
- advisoryhttp://secunia.com/secunia_research/2009-12/
- advisoryADV-2009-1540
Description
Integer overflow in Excel in Microsoft Office 2000 SP3, Office XP SP3, Office 2003 SP3, and Office 2004 and 2008 for Mac; Excel in 2007 Microsoft Office System SP1 and SP2; Open XML File Format Converter for Mac; Microsoft Office Excel Viewer 2003 SP3; Microsoft Office Excel Viewer; Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2; and Microsoft Office SharePoint Server 2007 SP1 and SP2 allows remote attackers to execute arbitrary code via an Excel file with a Shared String Table (SST) record with a numeric field that specifies an invalid number of unique strings, which triggers a heap-based buffer overflow, aka "Record Integer Overflow Vulnerability."
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Oct 18, 2012 | n/a | Not reported |
Affected Products
16 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OfficeMicrosoft | 2004, 2008, xp-sp3 | n/a |
| Office Compatibility Pack For Word Excel Ppt 2007Microsoft | See advisory | n/a |
| Office ExcelMicrosoft | 2000-sp3, 2003-sp3, 2007-sp1, 2007-sp2 | n/a |
| Office Excel ViewerMicrosoft | 2003-sp3 | n/a |
| Office Sharepoint ServerMicrosoft | 2007-sp1, 2007-sp2 | n/a |
Timeline
Publicly disclosed
Jun 10, 2009
Added to Industry KEV feed
Oct 18, 2012
Last updated
Apr 22, 2026
Weakness Type
- CWE-189
References
- advisorysecunia.com · 2009-12
- advisoryADV-2009-1540
- exploitVulnCheck exploitation report
- other20090609 Microsoft Excel SST Record Integer Overflow Vulnerability
- other54957
FAQ
Common Questions.
Integer overflow in Excel in Microsoft Office 2000 SP3, Office XP SP3, Office 2003 SP3, and Office 2004 and 2008 for Mac; Excel in 2007 Microsoft Office System SP1 and SP2; Open XML File Format Converter for Mac; Microsoft Office Excel Viewer 2003 SP3; Microsoft Office Excel Viewer; Microsoft Office Compatibility Pack…
Affected: Office (Microsoft) versions 2004, 2008, xp-sp3; Office Compatibility Pack For Word Excel Ppt 2007 (Microsoft); Office Excel (Microsoft) versions 2000-sp3, 2003-sp3, 2007-sp1, 2007-sp2, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Oct 18, 2012.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2009-0561 On Your Attack Surface?
Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.
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