SYSTEM privilege escalation via window-object type confusion
Published Jan 11, 2022 · Updated Aug 15, 2026
Win32k type confusion in affected Microsoft Windows releases allows local users to execute arbitrary code with SYSTEM privileges. During a user-mode callback, xxxClientAllocWindowClassExtraBytes accepts an unchecked return value after NtUserConsoleControl changes tagWND.pExtraBytes from a pointer to an offset, enabling out-of-bounds kernel memory access. A low-privileged local process can convert the resulting primitive into arbitrary kernel writes and full SYSTEM control without user interaction.
Summary
What happened
Win32k type confusion in affected Microsoft Windows releases allows local users to execute arbitrary code with SYSTEM privileges. During a user-mode callback, xxxClientAllocWindowClassExtraBytes accepts an unchecked return value after NtUserConsoleControl changes tagWND.pExtraBytes from a pointer to an offset, enabling out-of-bounds kernel memory access. A low-privileged local process can convert the resulting primitive into arbitrary kernel writes and full SYSTEM control without user interaction.
The record
- CVE
- CVE-2022-21882
- Published
- Jan 11, 2022
- Updated
- Aug 15, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-787, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 11, 2022CVE publishedPublication date reported by the CVE source.
- Aug 15, 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=10.0.17763.0 <10.0.17763.2452
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
Public exploit references
- Win32k ConsoleControl Offset Confusion Metasploit moduleweaponized · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog listingknown exploited catalog
Technologies
Your stack
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Your stack
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