Windows Common Log File System Driver Elevation of Privilege Vulnerability

cisa required action Apply updates per vendor instructions.

1. 2023-04-11 0-day patched (Project Zero)
2. 2023-04-11 First public exploit (Metasploit exploit/windows/local/cve_2023_28252_clfs_driver)
3. 2023-04-11 Added to CISA KEV
4. 2023-04-11 Published
5. 2023-05-02 CISA patch deadline
6. 2024-05-30 CISA SSVC: exploitation active

Added

3 y ago (2023-04-11)

Patch by

2023-05-02 (3 y ago)

Ransomware

Known to be used in ransomware campaigns

Required action

Apply updates per vendor instructions.

Vendor, product

Microsoft, Windows

CISA name

Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability

Detected in real attacks while still unknown to the vendor and the public, per Google Project Zero's 0day In-the-Wild tracker.

Patched

2023-04-11

Details

project zero root cause analysis

Groups reported to have exploited it in intrusions.

• Nokoyawa ransomware gang

reported by securelist.com

Ransomware Vulnerability Matrix by BushidoUK (github.com/BushidoUK/Ransomware-Vulnerability-Matrix), reformatted per CVE. CC BY 4.0

How it is exploited and what it leads to, in MITRE ATT&CK terms.

• T1078 Valid Accounts exploitation
• T1068 Exploitation for Privilege Escalation primary impact
• T1003 OS Credential Dumping secondary impact
• T1021 Remote Services secondary impact
• T1059 Command and Scripting Interpreter secondary impact
• T1136 Create Account secondary impact
• T1486 Data Encrypted for Impact secondary impact

kev release 2025-07-28, att&ck v16.1. KEV to ATT&CK mappings by the MITRE Center for Threat-Informed Defense (Mappings Explorer, Apache-2.0). © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. Terms of use

Exploitation

Active, exploited in the wild

Automatable

no

Technical impact

total

Assessed

2 y ago (2024-05-30)

48.89% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

• Metasploit exploit/windows/local/cve_2023_28252_clfs_driver Windows Common Log File System Driver (clfs.sys) Elevation of Privilege Vulnerability metasploit exploit, good rank, 2023-04-11
• packetstormsecurity.com http://packetstormsecurity.com/files/174668/Windows-Common-Log-File-System-Driver-clfs.sys-Privilege-Escalation.html referenced PoC, tagged "exploit" by a source, unverified

• Microsoft Windows 10 Version 1809
• Microsoft Windows Server 2019
• Microsoft Windows Server 2019 (Server Core installation)
• Microsoft Windows Server 2022
• Microsoft Windows 10 Version 20H2
• Microsoft Windows 11 version 21H2
• Microsoft Windows 10 Version 21H2
• Microsoft Windows 11 version 22H2
• Microsoft Windows 10 Version 22H2
• Microsoft Windows 10 Version 1507
• Microsoft Windows 10 Version 1607
• Microsoft Windows Server 2016
• Microsoft Windows Server 2016 (Server Core installation)
• Microsoft Windows Server 2008 Service Pack 2
• Microsoft Windows Server 2008 Service Pack 2 (Server Core installation)
• Microsoft Windows Server 2008 Service Pack 2
• Microsoft Windows Server 2008 R2 Service Pack 1
• Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation)
• Microsoft Windows Server 2012
• Microsoft Windows Server 2012 (Server Core installation)
• Microsoft Windows Server 2012 R2
• Microsoft Windows Server 2012 R2 (Server Core installation)

Weakness

• CWE-122 Heap-based Buffer Overflow
• CWE-787 Out-of-bounds Write

• msrc.microsoft.com /update-guide/vulnerability/CVE-2023-28252

  vendor-advisory, patch

• packetstormsecurity.com /files/174668/Windows-Common-Log-File-System-Driver-clfs.sys-Privilege-Escalation.html

  exploit, third-party-advisory, vdb-entry

• cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-28252

  government-resource, us-government-resource

• CVE List CVE-2023-28252
• NVD CVE-2023-28252

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.