CVE-2009-0563 — Microsoft Office Buffer Overflow Vulnerability
Stack-based buffer overflow in Microsoft Office Word 2002 SP3, 2003 SP3, and 2007 SP1 and SP2; Microsoft Office for Mac 2004 and 2008; Open XML File Format Converter for Mac; Microsoft Office Word Viewer 2003 SP3; Microsoft Office Word Viewer; and Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1 and SP2 allows remote attackers to execute arbitrary code via a Word document with a crafted tag containing an invalid length field, aka "Word Buffer Overflow Vulnerability."
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- EPSS 62.8% (30-day exploitation probability)+15
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — docs.microsoft.com (NIST National Vulnerability Database)
CISA required action CISA
Apply updates per vendor instructions.
US federal deadline: Jun 22, 2022 — passed 1576 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Microsoft Office, Microsoft Office Compatibility Pack, Microsoft Office Word Viewer…).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- Apply the fixed version or the patch documented under Remediation.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Microsoft | Office | version 2000-sp3version 2003-sp3version 2004version 2007-sp1version 2007-sp2version 2008version xp-sp3 | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Office Compatibility Pack | version 2007-sp1version 2007-sp2 | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Office Word Viewer | versions not specified by the sourceversion 2003-sp3 | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Open Xml File Format Converter | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
| 9.3 | CVSS 2.0 | High | 8.6 | 10.0 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 62.83%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
- Hunt retroactively in logs from before Jun 8, 2022 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · microsoft/office, microsoft/office compatibility pack, microsoft/office word viewer, microsoft/open xml file format conv
- Source status changed · Published → Analyzed
- Record published
- CVSS changed · 7.8
- Source status changed · → Published
- SSVC assessment updated
- Added to CISA KEV (detected)
- Record created in this database
- 2022
- Added to CISA KEV catalog
- 2009
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 3× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
12 on the record
- docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-027
- www.cisa.gov/known-exploited-vulnerabilities-catalog
- github.com/advisories/GHSA-f5c7-c9q4-9h6j
- nvd.nist.gov/vuln/detail/CVE-2009-0563
- www.us-cert.gov/cas/techalerts/TA09-160A.html
- www.securityfocus.com/bid/35188
- www.vupen.com/english/advisories/2009/1546
- oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6133
- osvdb.org/54959
- www.zerodayinitiative.com/advisories/ZDI-09-035
- www.securityfocus.com/archive/1/504204/100/0/threaded
- www.securitytracker.com/id
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-47293 Microsoft Office Click-To-Run Elevation of Privilege Vulnerability Jun 9, 2026
- Medium CVE-2026-42832 Microsoft Office Spoofing Vulnerability May 12, 2026
- High CVE-2026-42831 Microsoft Office Remote Code Execution Vulnerability May 12, 2026
- Medium CVE-2026-40421 Microsoft Word Information Disclosure Vulnerability May 12, 2026
- High CVE-2026-40419 Microsoft Office Click-To-Run Elevation of Privilege Vulnerability May 12, 2026
- High CVE-2026-40420 Microsoft Office Click-To-Run Elevation of Privilege Vulnerability May 12, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2009-0563 is "Microsoft Office Buffer Overflow Vulnerability", rated High. It affects Office (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 62.83% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.