Threats / Microsoft / CVE-2023-21674
CVE-2023-21674
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Windows vulnerability
Microsoft Windows ALPC use-after-free vulnerability enables local privilege escalation. Actively exploited in the wild.
Verdict
Today item — known-exploited.
A use-after-free flaw in Windows Advanced Local Procedure Call allows authenticated local attackers to escalate privileges to system level. Active exploitation confirms operational risk despite moderate EPSS score.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit 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
6 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 2023-01-10).
Probability (EPSS)
EPSS 0.41538 — 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.
Weakness (CWE)
Mapped to CWE-416 Use After Free — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution 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 board1
Front door — unauthenticated access narrative 1
Attacker
I gain initial access to a Windows system as a standard user through phishing, weak credentials, or lateral movement.
Business
Attacker establishes foothold within corporate network perimeter with user-level permissions.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I craft a malicious ALPC message that triggers a use-after-free condition in the kernel, causing memory corruption.
Business
Vulnerability becomes exploitation vector requiring no additional user interaction or social engineering.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute arbitrary code in kernel context and obtain SYSTEM privileges on the compromised machine.
Business
Attacker gains unrestricted control over the endpoint, enabling malware deployment, data exfiltration, and lateral movement to critical systems.
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