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Threats / Microsoft / CVE-2009-0563
CVE-2009-0563 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

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 · 2022-06-083EPSS 0.63081 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported 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).
CISA KEV ↗Confirmed
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
Affected: Microsoft, Office. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-119 Memory Buffer Bounds Error — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution 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 board
1

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

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • 2 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Catalogued by microsoft (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by microsoftCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.