CVE-2023-21674 | Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability

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

Published: 2023-01-10 Last update: 2025-10-30 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-21674 is rated Critical Active Threat (93.2/100): CVSS High severity, with high exploitation likelihood (EPSS 19.71%, 96th percentile). CISA KEV confirms active exploitation (added 2023-01-10) affecting Microsoft / Windows. a weakness (CWE-416) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2023-21674

Name: Microsoft Windows Advanced Local Procedure Call (ALPC) Privilege Escalation Vulnerability · CISA KEV detail

Exploit added: 2023-01-10

Action due: 2023-01-31

Required action: Apply updates per vendor instructions.

Exploit prediction scoring system (EPSS) score for CVE-2023-21674

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-10 20.12% 19.71% -0.42%
2 2026-06-08 16.99% 20.12% +3.14%
3 2026-05-28 — 16.99% —

Full EPSS history (41 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-21674

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.0 6.0 [email protected]

Weakness enumeration for CVE-2023-21674

Affected software / configurations for CVE-2023-21674

Vendor Product Version Raw CPE
microsoft windows_10_1507 < 10.0.10240.19685 cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*
microsoft windows_10_1607 < 10.0.14393.5648 cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*
microsoft windows_10_1809 < 10.0.17763.3887 cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*
microsoft windows_10_20h2 < 10.0.19042.2486 cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*
microsoft windows_10_21h2 < 10.0.19044.2486 cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*
microsoft windows_10_22h2 < 10.0.19045.2486 cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*
microsoft windows_11_21h2 < 10.0.22000.1455 cpe:2.3:o:microsoft:windows_11_21h2:*:*:*:*:*:*:*:*
microsoft windows_11_22h2 < 10.0.22621.1105 cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*
microsoft windows_rt_8.1 — cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
microsoft windows_server_2012 r2 cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
microsoft windows_server_2016 < 10.0.14393.5648 cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
microsoft windows_server_2019 < 10.0.17763.3887 cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
microsoft windows_server_2022 < 10.0.20348.1487 cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*

References for CVE-2023-21674

cvelogic Threat Intelligence