CVE-2023-21674 Microsoft Windows Advanced Local Procedure Call (ALPC) Privilege Escalation
An attacker can exploit a use-after-free flaw in Windows ALPC to elevate privileges on affected systems.
- Exploited in the wild
- Since 10 Jan 2023
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2023-21674?
CVE-2023-21674 is a high-severity use after free vulnerability in Microsoft Windows 10 1507, published on 10 Jan 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability
Weakness: CWE-416
Which versions are affected by CVE-2023-21674?
It affects 13 products.
Products include Microsoft Windows 10 1507, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 20h2, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2 and 7 more.
How do I fix CVE-2023-21674?
No fix has been published for CVE-2023-21674 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 31 Jan 2023.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2023-21674 being exploited?
Yes. Attackers have exploited CVE-2023-21674 in the wild since at least 10 Jan 2023.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Microsoft Windows 10 1507
- CVE-2017-8543 Microsoft Windows Search Remote Code Execution
- CVE-2025-33053 Microsoft Windows External Control of File Name or Path
- CVE-2025-33073 Microsoft Windows SMB Client Improper Access Control
- CVE-2024-49039 Microsoft Windows Task Scheduler Privilege Escalation
- CVE-2024-43461 Microsoft Windows MSHTML Platform Spoofing
Sources
Also known as GHSA-hqxf-h392-6m7w.