Privilege escalation via completion-context use-after-free
Published Jan 11, 2022 · Updated Jan 2, 2025
Use-after-free in the Windows kernel allows local users on affected Windows 8.1 and later releases to elevate privileges through a file-I/O race. Kernel file-I/O paths use a FILE_OBJECT completion context without holding a usage reference while a racing thread replaces and frees it. Successful exploitation requires local low-privilege code and controlled thread timing; the demonstrated trigger can instead crash the machine.
Summary
What happened
Use-after-free in the Windows kernel allows local users on affected Windows 8.1 and later releases to elevate privileges through a file-I/O race. Kernel file-I/O paths use a FILE_OBJECT completion context without holding a usage reference while a racing thread replaces and frees it. Successful exploitation requires local low-privilege code and controlled thread timing; the demonstrated trigger can instead crash the machine.
The record
- CVE
- CVE-2022-21881
- Published
- Jan 11, 2022
- Updated
- Jan 2, 2025
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-362, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 11, 2022CVE publishedPublication date reported by the CVE source.
- Sep 15, 2022Exploitation reportedCISA Known Exploited Vulnerabilities catalog inclusion
- Jan 2, 2025Record 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 <10.0.10240.19177
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.
Weakness, pattern, technique
Public exploit references
- Race against the Sandbox crash proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities catalog inclusionknown exploited catalog
Technologies
Your stack
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Your stack
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