Threats / Microsoft / CVE-2009-0563
CVE-2009-0563
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Microsoft Office vulnerability
Microsoft Office buffer overflow in Word document processing allows remote code execution through crafted tags with invalid length fields.
Verdict
Today item — known-exploited.
A buffer overflow in Office's document parsing enables attackers to execute arbitrary code by sending specially crafted Word files. The vulnerability is actively exploited in the wild with high EPSS score, posing significant risk to users opening untrusted documents.
CISA KEV Yes · 2022-06-084EPSS 0.63081 (verify live)5CVSS 7.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
2 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-06-08).
Probability (EPSS)
EPSS 0.63081 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.8 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) · Affected: Microsoft, Office. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-119 Memory Buffer Bounds Error — weakness family: Memory safety.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 4746 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a Word document with a malicious tag containing an invalid length field to trigger a buffer overflow.
Business
Users are exposed to remote code execution when opening email attachments or downloaded documents from untrusted sources.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I send the weaponized document to target users via email or host it on a compromised website.
Business
Attackers gain initial system access and can establish persistence, leading to data theft, malware installation, or lateral movement.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute arbitrary code with the privileges of the user running Office.
Business
Organizational systems become compromised, potentially affecting sensitive documents, intellectual property, and business continuity.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05