CVE-2023-33128

Local code execution via uninitialized memory free

Published Jun 13, 2023 · Updated Jan 1, 2025

Use-after-free in Microsoft .NET, Visual Studio, and PowerShell allows local users to execute code through generated P/Invoke cleanup logic. The P/Invoke source generator emits cleanup code that can free an uninitialized native value, causing the generated application to access already-released memory. Exploitation requires local low-privileged access and user interaction with affected generated code; the immediate documented consequence is a process crash, while Microsoft classifies the issue as remote code execution.

CVSS severity7.3
High
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Microsoft .NET, Visual Studio, and PowerShell allows local users to execute code through generated P/Invoke cleanup logic. The P/Invoke source generator emits cleanup code that can free an uninitialized native value, causing the generated application to access already-released memory. Exploitation requires local low-privileged access and user interaction with affected generated code; the immediate documented consequence is a process crash, while Microsoft classifies the issue as remote code execution.

The record

CVE
CVE-2023-33128
Published
Jun 13, 2023
Updated
Jan 1, 2025
Vendor
Microsoft
Product
.NET 6.0
Classifications
CWE-416, T1203
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 13, 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

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Is a vulnerable build present?

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

  1. Affected versionversion=6.0.0 <6.0.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · .NET 6.0version=6.0.0 <6.0.18
Microsoft · PowerShell 7.3version=7.3.0 <7.3.5
Microsoft · Microsoft Visual Studio 2022 version 17.6version=17.6.0 <17.6.3
Microsoft · Microsoft Visual Studio 2022 version 17.4version=17.4.0 <17.4.8
Microsoft · Microsoft Visual Studio 2022 version 17.0version=17.0.0 <17.0.22
Microsoft · Microsoft Visual Studio 2022 version 17.2version=17.2.0 <17.2.16
Microsoft · .NET 7.0version=7.0.0 <7.0.7

Published CVSS scores

7.3Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:R/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

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

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Your stack

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