CVE-2023-38171Network attack vector

Server process crash via version negotiation packet

Published Oct 10, 2023 · Updated Apr 14, 2025

NULL pointer dereference in Microsoft MsQuic before 2.2.3 allows remote attackers to crash a server process with a crafted QUIC packet. QuicConnRecvHeader accepts a Version Negotiation packet on a server connection and enters client-only processing that dereferences a null pointer. An unauthenticated network peer must reach an application using MsQuic server functionality; exploitation terminates that process without exposing or altering data.

CVSS severity7.5
High
EPSS probability69.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
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

NULL pointer dereference in Microsoft MsQuic before 2.2.3 allows remote attackers to crash a server process with a crafted QUIC packet. QuicConnRecvHeader accepts a Version Negotiation packet on a server connection and enters client-only processing that dereferences a null pointer. An unauthenticated network peer must reach an application using MsQuic server functionality; exploitation terminates that process without exposing or altering data.

The record

CVE
CVE-2023-38171
Published
Oct 10, 2023
Updated
Apr 14, 2025
Vendor
Microsoft
Product
Microsoft Visual Studio 2022 version 17.7
Classifications
CWE-476, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 14, 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=17.7.0 <17.7.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Visual Studio 2022 version 17.7version=17.7.0 <17.7.6
Microsoft · PowerShell 7.3version=7.3.0 <7.3.9
Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.2538
Microsoft · Microsoft Visual Studio 2022 version 17.6version=17.6.0 <17.6.9
Microsoft · Microsoft Visual Studio 2022 version 17.4version=17.4.0 <17.4.13
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.2428
Microsoft · Microsoft Visual Studio 2022 version 17.2version=17.2.0 <17.2.21
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.2031
Microsoft · .NET 7.0version=7.0.0 <7.0.13

Published CVSS scores

7.5Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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

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