SYSTEM privilege escalation via UserManager link following
Published Apr 9, 2024 · Updated May 3, 2025
Improper link resolution in Microsoft Windows Authentication allows local users to gain SYSTEM privileges through UserManager file reads. The UserManager service reads files from a user-controlled directory as NT AUTHORITY\SYSTEM and follows attacker-controlled links, exposing SAM, SYSTEM, and SECURITY registry hives from shadow copies. Low-privileged local access is required, and successful exploitation exposes credential and security data with SYSTEM-level authority.
Summary
What happened
Improper link resolution in Microsoft Windows Authentication allows local users to gain SYSTEM privileges through UserManager file reads. The UserManager service reads files from a user-controlled directory as NT AUTHORITY\SYSTEM and follows attacker-controlled links, exposing SAM, SYSTEM, and SECURITY registry hives from shadow copies. Low-privileged local access is required, and successful exploitation exposes credential and security data with SYSTEM-level authority.
The record
- CVE
- CVE-2024-21447
- Published
- Apr 9, 2024
- Updated
- May 3, 2025
- Vendor
- Microsoft
- Product
- Windows 11 version 21H2
- Classifications
- CWE-59, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 9, 2024CVE publishedPublication date reported by the CVE source.
- May 3, 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=10.0.0 <10.0.22000.2899
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
- UserManager_Readproof of concept · unverified
- UserManagerEoPproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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