CVE-2025-32701: Windows 10 1507 Privilege Escalation Flaw

CVE-2025-32701 Overview

Use after free in Windows Common Log File System Driver allows an authorized attacker to elevate privileges locally.

Critical Impact

This vulnerability can lead to local privilege escalation, compromising system integrity and allowing attackers to gain unauthorized access.

Affected Products

• Microsoft Windows 10 1507
• Microsoft Windows 11 22H2
• Microsoft Windows Server 2025

Discovery Timeline

• 2025-05-13 - CVE CVE-2025-32701 published to NVD
• 2025-10-27 - Last updated in NVD database

Technical Details for CVE-2025-32701

Vulnerability Analysis

The vulnerability is a use after free condition in the Windows Common Log File System (CLFS) driver. This flaw allows an attacker to exploit previously deallocated memory, leading to potential privilege escalation on affected Windows systems.

Root Cause

The root cause of the vulnerability is improper handling of memory objects within the CLFS subsystem. After certain operations, the associated memory is not correctly freed, allowing attackers to manipulate it maliciously.

Attack Vector

This is a local attack vector. An attacker with local access can exploit this vulnerability using specially crafted inputs that trigger the flaw within the CLFS driver.

// Example exploitation code (sanitized)
#include <windows.h>

int main() {
    // Attempt to target deallocated memory
    HANDLE hFile = CreateFile("\\.\C:\path\to\target", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
    // Further exploitation steps
    // ...
    CloseHandle(hFile);
    return 0;
}

Detection Methods for CVE-2025-32701

Indicators of Compromise

• Unexpected CLFS.sys log entries
• Frequent system crashes or BSODs
• Unauthorized privilege escalation events

Detection Strategies

Monitoring anomalous behavior such as irregular access patterns to memory, or frequent crashes in processes utilizing CLFS can be an effective strategy. Detection systems should be configured to log and alert on such activities.

Monitoring Recommendations

Utilize tools such as Windows Event Viewer to monitor for system errors and warnings related to CLFS. Advanced Threat Detection systems like SentinelOne can correlate multiple indicators to highlight malicious activity.

How to Mitigate CVE-2025-32701

Immediate Actions Required

• Disable affected CLFS services temporarily if operationally feasible
• Restrict local access to servers running affected Windows versions
• Regularly monitor for exploitation attempts and system anomalies

Patch Information

Users should apply the latest security patches released by Microsoft as outlined in their security advisory. Refer to the Vendor Advisory for more details.

Workarounds

Restrict execution of non-essential code in contexts where the CLFS driver might be used.

# Configuration example
echo "Restricting access to Comb Locker services for non-admin users"
Set-Service -Name 'clfs' -StartupType Disabled