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Threats / Microsoft / CVE-2018-8453
CVE-2018-8453 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Win32k vulnerability

Microsoft Windows Win32k privilege escalation vulnerability exploited in active ransomware campaigns.

Verdict

Today item, not a backlog item.

CVE-2018-8453 is a privilege escalation flaw in Win32k that has been actively exploited in the wild as part of ransomware operations. The vulnerability enables attackers to elevate permissions from lower to higher privilege levels on affected Windows systems.

CISA KEV Yes · 2022-01-213Ransomware use Flagged3EPSS 0.73106 (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
23 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 2022-01-21), flagged for known ransomware use.
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.73106 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Win32k. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-404 CWE-404 — weakness family: Resource / availability.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-404 · CWE-404Resource / availability
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 gain initial access to a Windows system through phishing, drive-by download, or other infection vector.
Business
Endpoint security perimeter is breached; malware execution begins with limited user privileges.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I exploit CVE-2018-8453 in Win32k to escalate my process privileges from user-level to system or kernel level.
Business
Attacker obtains administrative control; security restrictions and access controls are bypassed.
3

Lateral reach — past segmentation narrative 3

Attacker
I deploy ransomware payload with elevated privileges, encrypting files and disabling recovery mechanisms.
Business
Critical business data becomes inaccessible; operations halt and ransom demands are issued.
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)
  • Ransomware-use flag (CISA)
  • EPSS probability (FIRST)
  • Public PoC available (VulnCheck)
  • 23 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.