Cyber Resilience

CVE-2023-21674

HighCISA KEVActive ExploitationEUVD Exploited

Published: 10 January 2023

Published
10 January 2023
Modified
30 October 2025
KEV Added
10 January 2023
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.1971 95.6th percentile
Risk Priority 49 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-21674 is a high-severity Use After Free (CWE-416) vulnerability in Microsoft Windows 10 1507. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 4.4% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and AC-6 (Least Privilege).

Deeper analysis

Windows Advanced Local Procedure Call (ALPC) contains an elevation-of-privilege vulnerability tracked as CVE-2023-21674 and assigned CWE-416. The flaw resides in a core Windows kernel component and carries a CVSS 3.1 score of 8.8, reflecting local attack vector, low complexity, and low privileges required.

An authenticated local attacker can trigger the use-after-free condition to obtain SYSTEM-level privileges on an affected Windows system, resulting in full compromise of confidentiality, integrity, and availability with scope change across security boundaries.

Microsoft has published patches through its Security Response Center update guide, and the vulnerability appears in the CISA Known Exploited Vulnerabilities catalog, confirming in-the-wild exploitation. The associated EPSS score has remained essentially flat near 0.20 since disclosure, indicating no material post-publication surge in observed exploitation attempts.

EU & UK References

Vulnerability details

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

CWE(s)
KEV Date Added
10 January 2023

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
windows 10 1507
≤ 10.0.10240.19685
microsoft
windows 10 1607
≤ 10.0.14393.5648
microsoft
windows 10 1809
≤ 10.0.17763.3887
microsoft
windows 10 20h2
≤ 10.0.19042.2486
microsoft
windows 10 21h2
≤ 10.0.19044.2486
microsoft
windows 10 22h2
≤ 10.0.19045.2486
microsoft
windows 11 21h2
≤ 10.0.22000.1455
microsoft
windows 11 22h2
≤ 10.0.22621.1105
microsoft
windows rt 8.1
all versions
microsoft
windows server 2012
r2
+3 more product configuration(s) — see NVD for full list

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires timely application of vendor patches that eliminate the use-after-free flaw in ALPC before local attackers can exploit it.

prevent

Enforces least-privilege restrictions so a low-privileged account cannot reach the code paths needed to trigger the ALPC EoP.

prevent

Applies memory-protection mechanisms that can block or contain use-after-free exploitation attempts within Windows kernel components.

References