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Threats / Microsoft / CVE-2018-8440
CVE-2018-8440 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft Windows vulnerability

Windows improperly handles Advanced Local Procedure Call (ALPC) requests, allowing local attackers to elevate privileges. This vulnerability has been exploited in ransomware campaigns.

Verdict

Today item, not a backlog item.

A local privilege escalation flaw in Windows ALPC handling with confirmed active exploitation and ransomware deployment. Requires local access but enables full system compromise from unprivileged context.

CISA KEV Yes · 2022-03-283Ransomware use Flagged3EPSS 0.1853 (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
7 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 2022-03-28), flagged for known ransomware use.
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.1853 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.
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 gain initial access to a Windows system with limited user privileges through phishing, malware delivery, or supply chain compromise.
Business
An attacker establishes a foothold on corporate endpoints, bypassing perimeter controls.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I exploit the ALPC handling flaw to escalate my privileges from standard user to SYSTEM level.
Business
The attacker gains unrestricted control over the compromised machine, defeating application sandboxing and user account isolation.
3

Lateral reach — past segmentation narrative 3

Attacker
I deploy ransomware or other malicious payloads with full system privileges.
Business
Critical business systems become encrypted or compromised, leading to operational shutdown, data loss, and extortion demands.
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)
  • 7 reported-exploitation source(s)
  • 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.