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Threats / Microsoft / CVE-2023-28229
CVE-2023-28229 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Windows CNG Key Isolation Service vulnerability

Microsoft Windows CNG Key Isolation Service contains an unspecified vulnerability allowing attackers to gain limited SYSTEM privileges through improper resource handling.

Verdict

Today item — known-exploited.

A privilege escalation flaw in Windows CNG Key Isolation Service enables local attackers to obtain elevated SYSTEM-level access. Active exploitation in the wild indicates immediate risk to Windows systems requiring prompt patching.

CISA KEV Yes · 2023-10-043EPSS 0.01872 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
1 independent public report of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
cisa.gov ↗Confirmed
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-10-04).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.01872 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Windows CNG Key Isolation Service. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-591 CWE-591.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 execute code with standard user privileges on a target Windows system.
Business
User workstations and servers remain vulnerable to local privilege escalation attacks.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I trigger the vulnerability in the CNG Key Isolation Service to escalate my privileges to SYSTEM level.
Business
Attackers gain unrestricted control over affected systems, enabling lateral movement and persistence.
3

Lateral reach — past segmentation narrative 3

Attacker
I access cryptographic keys and sensitive system resources now available at SYSTEM privilege level.
Business
Confidentiality and integrity of encrypted data and system security controls are compromised.
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)
  • Public PoC available (VulnCheck)
  • 1 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • 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.