Local privilege escalation in Fast FAT driver
Published Nov 10, 2021 · Updated Aug 19, 2026
Improper privilege management in Microsoft's Fast FAT driver allows local users to elevate privileges on affected Windows releases. Microsoft has not disclosed the specific driver routine or the incorrect operation on attacker-controlled FAT file-system input. Low-privileged local access is required, and successful exploitation executes in an elevated security context.
Summary
What happened
Improper privilege management in Microsoft's Fast FAT driver allows local users to elevate privileges on affected Windows releases. Microsoft has not disclosed the specific driver routine or the incorrect operation on attacker-controlled FAT file-system input. Low-privileged local access is required, and successful exploitation executes in an elevated security context.
The record
- CVE
- CVE-2021-41377
- Published
- Nov 10, 2021
- Updated
- Aug 19, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-269, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 10, 2021CVE publishedPublication date reported by the CVE source.
- Aug 19, 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 <10.0.10240.19119
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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