CVE-2023-33163

Adjacent-network code execution

Published Jul 11, 2023 · Updated Jan 1, 2025

Remote code execution in Microsoft Windows Server Network Load Balancing allows remote attackers on an adjacent network to run code. Microsoft has not published the vulnerable function, packet format, or incorrect operation within the NLB networking driver. Exposure requires the optional NLB feature to be installed and the attacker to have adjacent-network access; successful code execution can compromise the server.

CVSS severity7.5
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in Microsoft Windows Server Network Load Balancing allows remote attackers on an adjacent network to run code. Microsoft has not published the vulnerable function, packet format, or incorrect operation within the NLB networking driver. Exposure requires the optional NLB feature to be installed and the attacker to have adjacent-network access; successful code execution can compromise the server.

The record

CVE
CVE-2023-33163
Published
Jul 11, 2023
Updated
Jan 1, 2025
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-591, T1210
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 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=10.0.17763.0 <10.0.17763.4645

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.4645
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.6085
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.24374
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.24374
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.6085
Microsoft · Windows Server 2008 R2 Service Pack 1version=6.1.7601.0 <6.1.7601.26623
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)version=6.1.7601.0 <6.1.7601.26623
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.21063
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.4645
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.1850
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.21063

Published CVSS scores

7.5Microsoft CorporationCVSS:3.1/AV:A/AC:H/PR:N/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-591Sensitive Data Storage in Improperly Locked Memory
T1210Exploitation of Remote Services

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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