CVE-2023-21674

Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability

CVSS 3.1 High 8.8Known exploited (CISA KEV)

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C

Description

Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability

Key data

CVSS 3.1 High 8.8

Score published by microsoft in the CVE record.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C

Attack vector: Local
The attacker needs local access to the system, or to trick a user into running something.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: Low
A basic user account is needed.
User interaction: None
No action from any user is needed.
Scope: Changed
The impact can reach other components beyond the vulnerable one.
Confidentiality impact: High
Serious or total effect on the secrecy of data.
Integrity impact: High
Serious or total effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.

Metric	Value	What it means
Attack vector	Local	The attacker needs local access to the system, or to trick a user into running something.
Attack complexity	Low	No special conditions are needed. The attack can be repeated at will.
Privileges required	Low	A basic user account is needed.
User interaction	None	No action from any user is needed.
Scope	Changed	The impact can reach other components beyond the vulnerable one.
Confidentiality impact	High	Serious or total effect on the secrecy of data.
Integrity impact	High	Serious or total effect on the trustworthiness of data.
Availability impact	High	Serious or total effect on availability.

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.

EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score: 0.34206 (34.2% probability)
Percentile: 98.4%
Scores of: Nov 10, 2026
Model: v2026.06.15

CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog: Microsoft Windows Advanced Local Procedure Call (ALPC) Privilege Escalation Vulnerability
Added to the catalog: Jan 10, 2023
Federal due date: Jan 31, 2023

CISA assessment as of Jul 24, 2024

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation: Recorded by CISA as active
Automatable: no
Technical impact: total

Weakness (CWE)

CWE catalog version 5.0.

CWE-416Use After Free

Affected products

Products listed in the CVE record, as the CNA published them.

Microsoft Windows 10 Version 1809
- affected: 10.0.17763.0 up to before 10.0.17763.3887
Microsoft Windows 10 Version 1809
- affected: 10.0.0 up to before 10.0.17763.3887
Microsoft Windows Server 2019
- affected: 10.0.17763.0 up to before 10.0.17763.3887
Microsoft Windows Server 2019 (Server Core installation)
- affected: 10.0.17763.0 up to before 10.0.17763.3887
Microsoft Windows Server 2022
- affected: 10.0.20348.0 up to before 10.0.20348.1487
Microsoft Windows 10 Version 20H2
- affected: 10.0.0 up to before 10.0.19042.2486
Microsoft Windows 11 version 21H2
- affected: 10.0.0 up to before 10.0.22000.1455
Microsoft Windows 10 Version 21H2
- affected: 10.0.19043.0 up to before 10.0.19044.2486
Microsoft Windows 11 version 22H2
- affected: 10.0.22621.0 up to before 10.0.22621.1105
Microsoft Windows 10 Version 22H2
- affected: 10.0.19045.0 up to before 10.0.19045.2486
Microsoft Windows 10 Version 1507
- affected: 10.0.10240.0 up to before 10.0.10240.19685
Microsoft Windows 10 Version 1607
- affected: 10.0.14393.0 up to before 10.0.14393.5648
Microsoft Windows Server 2016
- affected: 10.0.14393.0 up to before 10.0.14393.5648
Microsoft Windows Server 2016 (Server Core installation)
- affected: 10.0.14393.0 up to before 10.0.14393.5648
Microsoft Windows 8.1
- affected: 6.3.0 up to before 6.3.9600.20778
Microsoft Windows Server 2012 R2
- affected: 6.3.9600.0 up to before 6.3.9600.20778
Microsoft Windows Server 2012 R2 (Server Core installation)
- affected: 6.3.9600.0 up to before 6.3.9600.20778

References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability (msrc.microsoft.com)vendor-advisory

Timeline

ID reservedDec 13, 2022
Record publishedJan 10, 2023
Added to CISA KEVJan 10, 2023
Record last updatedOct 21, 2025

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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:51 UTC. Sources and licenses