SYSTEM code execution via freed CLFS pointer
Published Jan 14, 2020 · Updated Aug 4, 2024
Use-after-free in Microsoft Windows CLFS.SYS allows local users to execute code as SYSTEM by opening a crafted binary log file. CLFS.SYS frees a pointer while processing attacker-controlled log data and later reuses that pointer, allowing controlled memory corruption. Exploitation requires prior low-privileged code execution on an affected Windows host, and successful abuse grants SYSTEM privileges.
Summary
What happened
Use-after-free in Microsoft Windows CLFS.SYS allows local users to execute code as SYSTEM by opening a crafted binary log file. CLFS.SYS frees a pointer while processing attacker-controlled log data and later reuses that pointer, allowing controlled memory corruption. Exploitation requires prior low-privileged code execution on an affected Windows host, and successful abuse grants SYSTEM privileges.
The record
- CVE
- CVE-2020-0634
- Published
- Jan 14, 2020
- Updated
- Aug 4, 2024
- Vendor
- Microsoft
- Product
- Windows 10 Version 1909
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 14, 2020CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=unspecified
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.
Public exploit references
- STAR Labs CLFS crash proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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