Local privilege escalation via unchecked CLFS block copy
Published Jun 10, 2025 · Updated Feb 26, 2026
A heap-based buffer overflow in the Windows Common Log File System Driver allows local users to gain administrator privileges. CClfsLogFcbPhysical::ReadLogBlock can pass an oversized read to CcCopyRead without checking that the data fits the remaining destination buffer. Exploitation requires medium-integrity code execution and a writable volume with a logical sector size above 512 bytes, and it corrupts adjacent kernel memory.
Summary
What happened
A heap-based buffer overflow in the Windows Common Log File System Driver allows local users to gain administrator privileges. CClfsLogFcbPhysical::ReadLogBlock can pass an oversized read to CcCopyRead without checking that the data fits the remaining destination buffer. Exploitation requires medium-integrity code execution and a writable volume with a logical sector size above 512 bytes, and it corrupts adjacent kernel memory.
The record
- CVE
- CVE-2025-32713
- Published
- Jun 10, 2025
- Updated
- Feb 26, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-122, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 10, 2025CVE publishedPublication date reported by the CVE source.
- Feb 26, 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 <10.0.10240.21034
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
- S2W CLFS pool-overflow demonstrationproof of concept · demonstrated
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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