# CVE-2023-21768 — Microsoft Windows Server 2022

> As of 2026-11-02, CVE-2023-21768 is a HIGH-severity vulnerability in Microsoft Windows Server 2022, CVSS v3.1 7.8, EPSS 65.4% (99.2th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2023-21768, most recently “Public PoC for Windows Ancillary Function Driver for WinSock (afd.sys) Privilege Escalation - CVE-2023-21768”.

**Last updated:** 2025-01-01

## What is CVE-2023-21768?

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

The record classifies CVE-2023-21768 under weakness class [CWE-822](https://intel.threadlinqs.com/cwe/CWE-822). Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 3 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 1397 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **EPSS (FIRST):** 65.4% probability of exploitation in the next 30 days, higher than 99.2% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 9.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2023-01-10, last modified 2025-01-01

## Is CVE-2023-21768 being exploited?

Weaponised exploit code for CVE-2023-21768 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.

- [chompie1337/Windows_LPE_AFD_CVE-2023-21768](https://github.com/chompie1337/Windows_LPE_AFD_CVE-2023-21768) (github)
- [SamuelTulach/nullmap](https://github.com/SamuelTulach/nullmap) (github)
- [Malwareman007/CVE-2023-21768](https://github.com/Malwareman007/CVE-2023-21768) (github)
- [cl4ym0re/cve-2023-21768-compiled](https://github.com/cl4ym0re/cve-2023-21768-compiled) (github)
- [P4x1s/CVE-2023-21768-POC](https://github.com/P4x1s/CVE-2023-21768-POC) (github)
- [zoemurmure/CVE-2023-21768-AFD-for-WinSock-EoP-exploit](https://github.com/zoemurmure/CVE-2023-21768-AFD-for-WinSock-EoP-exploit) (github)
- [xboxoneresearch/CVE-2023-21768-dotnet](https://github.com/xboxoneresearch/CVE-2023-21768-dotnet) (github)
- [h1bAna/CVE-2023-21768](https://github.com/h1bAna/CVE-2023-21768) (github)

## Affected products and versions

- [Microsoft](https://intel.threadlinqs.com/vendors/microsoft): Windows Server 2022, Windows 11 version 21H2, Windows 11 version 22H2

## How to fix CVE-2023-21768

Vendor advisory: [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21768](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21768). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2023-21768

1 tracked threat in the Threadlinqs corpus references CVE-2023-21768, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Public PoC for Windows Ancillary Function Driver for WinSock (afd.sys) Privilege Escalation - CVE-2023-21768](https://intel.threadlinqs.com/threat/TL-2026-5053) — HIGH · 2026-11-02

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-11-03. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [msrc.microsoft.com — vendor advisory](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21768)

Canonical: https://intel.threadlinqs.com/cve/CVE-2023-21768
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