CVE-2023-21768Known exploitationPublic exploit

Local privilege escalation via unvalidated kernel pointer

Published Jan 10, 2023 · Updated Jan 1, 2025

Untrusted pointer dereference in Microsoft Windows 11 and Windows Server 2022 allows local users to gain SYSTEM privileges. AfdNotifyRemoveIoCompletion writes through a user-controlled pointer without ProbeForWrite, enabling a fixed-value kernel write. Any local user able to issue the crafted AFD request can corrupt an I/O ring object, obtain arbitrary kernel read/write, and replace a process token.

CVSS severity7.8
High
EPSS probability65.42%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Untrusted pointer dereference in Microsoft Windows 11 and Windows Server 2022 allows local users to gain SYSTEM privileges. AfdNotifyRemoveIoCompletion writes through a user-controlled pointer without ProbeForWrite, enabling a fixed-value kernel write. Any local user able to issue the crafted AFD request can corrupt an I/O ring object, obtain arbitrary kernel read/write, and replace a process token.

The record

CVE
CVE-2023-21768
Published
Jan 10, 2023
Updated
Jan 1, 2025
Vendor
Microsoft
Product
Windows 11 version 21H2
Classifications
CWE-822, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 1, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.0 <10.0.22000.1455

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.1455
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.1105
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.1487

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-822Untrusted Pointer Dereference
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo