Cyber Resilience

CVE-2009-3129

Memory Safety in Microsoft Excel 2002 … 2007

CISA KEVActive ExploitationEUVD ExploitedPublic PoCMemory Safety
Published
11 November 2009
Modified
21 April 2026
KEV Added
03 March 2022
Patch / advisory
View advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.86 99.7th percentile
Risk Priority 83 floored blend · peak EPSS

Summary

CVE-2009-3129 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Microsoft Excel. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 0.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Microsoft Office Excel 2002 SP3, 2003 SP3, and 2007 SP1 and SP2, along with Office 2004 and 2008 for Mac, the Open XML File Format Converter for Mac, Office Excel Viewer 2003 SP3, Office Excel Viewer SP1 and SP2, and the Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2, contain a memory corruption vulnerability. The flaw, identified as CVE-2009-3129 and mapped to CWE-787, occurs when processing a spreadsheet containing a FEATHEADER record that supplies an invalid cbHdrData size element, resulting in an invalid pointer offset.

An attacker can supply a specially crafted spreadsheet file that, when opened by a user in any of the affected applications, triggers arbitrary code execution. The attack vector is local with no privileges required but depends on user interaction to open the document, producing a CVSS 3.1 score of 7.8 with high impact on confidentiality, integrity, and availability.

Public references list multiple exploit proofs-of-concept, including code published on Exploit-DB, confirming that working attack samples have been available since disclosure.

EU & UK References

Vulnerability Data

Microsoft Office Excel 2002 SP3, 2003 SP3, and 2007 SP1 and SP2; Office 2004 and 2008 for Mac; Open XML File Format Converter for Mac; Office Excel Viewer 2003 SP3; Office Excel Viewer SP1 and SP2; and Office Compatibility Pack…

more

for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2 allows remote attackers to execute arbitrary code via a spreadsheet with a FEATHEADER record containing an invalid cbHdrData size element that affects a pointer offset, aka "Excel Featheader Record Memory Corruption Vulnerability."

CWE(s)
CWE-787
KEV Date Added
03 March 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2010-3333Same product: Microsoft Officeboth on KEV
CVE-2009-0563Same product: Microsoft Officeboth on KEV
CVE-2015-2424Same product: Microsoft Excel Viewerboth on KEV
CVE-2015-1642Same product: Microsoft Officeboth on KEV
CVE-2018-0802Same product: Microsoft Officeboth on KEV
CVE-2018-0798Same product: Microsoft Officeboth on KEV
CVE-2015-1641Same product: Microsoft Officeboth on KEV
CVE-2014-1761Same product: Microsoft Officeboth on KEV
CVE-2012-1889Same product: Microsoft Officeboth on KEV
CVE-2020-0986Same vendor: Microsoftboth on KEV

Affected Assets

microsoft
excel
2002, 2003, 2007
microsoft
excel viewer
2003, all versions
microsoft
office
2004, 2008
microsoft
open xml file format converter
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect and prevent out-of-bounds write defects.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates practices that prevent out-of-bounds writes.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and safe memory handling.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles reduce the likelihood of buffer overflows.

A.8.28 Secure coding partial match
prevents

Secure coding directly addresses out-of-bounds writes through language choice and coding standards.

A.8.32 Change management partial match
prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References