Local privilege escalation via Win32k flaw
Published Sep 15, 2021 · Updated Aug 10, 2026
Elevation of privilege in Microsoft Windows Win32k allows local users to gain SYSTEM privileges. The flaw is in the Win32k kernel component, but Microsoft has not publicly disclosed the specific faulty operation or function for CVE-2021-38639. Exploitation requires local access and execution of a crafted process; no remote network path or user interaction is required.
Summary
What happened
Elevation of privilege in Microsoft Windows Win32k allows local users to gain SYSTEM privileges. The flaw is in the Win32k kernel component, but Microsoft has not publicly disclosed the specific faulty operation or function for CVE-2021-38639. Exploitation requires local access and execution of a crafted process; no remote network path or user interaction is required.
The record
- CVE
- CVE-2021-38639
- Published
- Sep 15, 2021
- Updated
- Aug 10, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 15, 2021CVE publishedPublication date reported by the CVE source.
- Aug 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.10240.0 <10.0.10240.19060
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
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.
Reported exploitation
- CVE-2021-38639 exploitationknown exploited catalog
Technologies
Your stack
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Your stack
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