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Threats / Microsoft / CVE-2023-21715
CVE-2023-21715 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Office vulnerability

Microsoft Office Publisher security feature bypass vulnerability allowing local authenticated attacks on targeted systems.

Verdict

Today item — known-exploited.

A local authenticated attacker can bypass security features in Microsoft Office Publisher. The vulnerability has been exploited in the wild, indicating active abuse despite requiring local access and prior authentication.

CISA KEV Yes · 2023-02-143EPSS 0.12107 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
5 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 2023-02-14).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.12107 — 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-863 Incorrect Authorization — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-863 · Incorrect AuthorizationAuthorization / access control
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 authenticate to a system where I have local user access.
Business
An insider or compromised account holder gains a foothold on corporate infrastructure.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I exploit the security feature bypass in Office Publisher to circumvent intended protections.
Business
Security controls designed to prevent unauthorized document manipulation or data exfiltration are rendered ineffective.
3

Lateral reach — past segmentation narrative 3

Attacker
I modify or extract sensitive content from Publisher documents without triggering expected safeguards.
Business
Confidential business documents, templates, or embedded data are compromised or altered without detection.
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)
  • 5 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.