CVE-2024-25088

Executive Summary

CVE-2024-25088 is a high-severity local privilege escalation vulnerability in Jungo WinDriver, a kernel-mode driver development toolkit. The flaw stems from improper privilege management, allowing a local attacker with low privileges to execute arbitrary code in the kernel context (NT AUTHORITY\SYSTEM). This can lead to full system compromise, including data exfiltration, malware installation, and persistence. The vulnerability affects all versions prior to 12.5.1. No public proof-of-concept (PoC) or exploit code has been released as of this report. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the impact is severe for affected systems.

CVSS Breakdown & Threat Level

• CVSS Score: 7.8 (High)
• Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Local (AV:L) – requires local access to the system.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: Low (PR:L) – attacker needs only user-level access.
• User Interaction: None (UI:N) – no user action needed.
• Scope: Unchanged (S:U) – vulnerability does not cross trust boundaries.
• Confidentiality, Integrity, Availability: High (C:H/I:H/A:H) – full compromise.

Threat Level: High. While local access is required, the low complexity and high impact make it a prime target for post-exploitation or insider threats.

Deep Dive & Mechanics

Jungo WinDriver provides a user-mode API to access hardware without writing kernel-mode drivers. It includes a kernel-mode driver (windrvr6.sys) that handles IOCTL requests from user-mode applications. The vulnerability lies in improper privilege validation within the driver's IOCTL handler.

Root Cause: The driver fails to properly verify the caller's privileges before performing privileged operations (e.g., memory mapping, physical memory access, or hardware configuration). A low-privileged user can send crafted IOCTL codes to the driver, causing it to execute arbitrary kernel-mode code or modify kernel memory.

Attack Flow:

1. Attacker gains local access (e.g., via malware, phishing, or legitimate user account).
2. Attacker opens a handle to the WinDriver device (\\.\WinDrvr6).
3. Attacker sends a malicious IOCTL request that triggers the privilege escalation.
4. The driver executes the request with kernel privileges, allowing the attacker to execute arbitrary code as SYSTEM.

Affected Component: The IOCTL dispatch routine in windrvr6.sys. The driver does not call SeSinglePrivilegeCheck or similar functions to validate the caller's token.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-12.5.1):

// Simplified IOCTL handler
NTSTATUS DriverDispatch( PDEVICE_OBJECT DeviceObject, PIRP Irp ) {
    PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
    ULONG ioctlCode = irpStack->Parameters.DeviceIoControl.IoControlCode;

    switch (ioctlCode) {
        case IOCTL_MAP_PHYSICAL_MEMORY:
            // No privilege check!
            MapPhysicalMemory(Irp);
            break;
        // ... other cases
    }
    return STATUS_SUCCESS;
}

Patched Code (12.5.1+):

NTSTATUS DriverDispatch( PDEVICE_OBJECT DeviceObject, PIRP Irp ) {
    PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);
    ULONG ioctlCode = irpStack->Parameters.DeviceIoControl.IoControlCode;

    // Added privilege check
    if (!SeSinglePrivilegeCheck(SeTcbPrivilege, ExGetPreviousMode())) {
        return STATUS_PRIVILEGE_NOT_HELD;
    }

    switch (ioctlCode) {
        case IOCTL_MAP_PHYSICAL_MEMORY:
            MapPhysicalMemory(Irp);
            break;
        // ... other cases
    }
    return STATUS_SUCCESS;
}

The patch adds a call to SeSinglePrivilegeCheck to ensure the caller has the SeTcbPrivilege (required for trusted computing base operations). This prevents unprivileged users from invoking sensitive IOCTLs.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Windows 10/11 x64 with Jungo WinDriver < 12.5.1 installed.
• Local user account (non-admin).
• Visual Studio or MinGW for compiling exploit.

Exploit Code (Conceptual):

#include <windows.h>
#include <stdio.h>

#define IOCTL_MAP_PHYSICAL_MEMORY CTL_CODE(FILE_DEVICE_UNKNOWN, 0x800, METHOD_NEITHER, FILE_ANY_ACCESS)

int main() {
    HANDLE hDevice = CreateFileA("\\\\.\\WinDrvr6", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
    if (hDevice == INVALID_HANDLE_VALUE) {
        printf("Failed to open device: %d\n", GetLastError());
        return 1;
    }

    // Craft input buffer to map physical memory at a critical address (e.g., HAL heap)
    // This would overwrite kernel structures to gain code execution.
    BYTE inputBuffer[0x100] = {0};
    // ... fill with malicious payload ...

    DWORD bytesReturned;
    DeviceIoControl(hDevice, IOCTL_MAP_PHYSICAL_MEMORY, inputBuffer, sizeof(inputBuffer), NULL, 0, &bytesReturned, NULL);

    printf("Exploit sent. Check for SYSTEM shell.\n");
    CloseHandle(hDevice);
    return 0;
}

Steps:

1. Compile the exploit as a console application.
2. Run it from a low-privileged command prompt.
3. If successful, the exploit will execute shellcode in kernel context, spawning a SYSTEM shell.

Note: No public exploit exists; this is a conceptual example.

Blue Team (Detection & Prevention)

Detection:

• Monitor for unusual IOCTL calls to \\.\WinDrvr6 from non-admin processes.
• Use Sysmon Event ID 11 (FileCreate) to detect dropped driver files.
• Enable Windows Defender Attack Surface Reduction (ASR) rules to block LSASS credential theft and process injection.

Prevention:

• Apply the vendor patch (upgrade to 12.5.1+).
• Restrict installation of WinDriver to authorized users only.
• Use AppLocker or WDAC to block untrusted drivers.
• Enable Driver Signature Enforcement.

Indicators of Compromise (IOCs)

Detection Engineering

YARA Rule

rule CVE_2024_25088_WinDriver_Escalation {
    meta:
        description = "Detects vulnerable Jungo WinDriver windrvr6.sys versions"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-25088"
    strings:
        $driver_name = "windrvr6.sys" nocase
        $version_string = "12.5.0" nocase
        $version_string2 = "12.4" nocase
        $version_string3 = "12.3" nocase
    condition:
        $driver_name and ($version_string or $version_string2 or $version_string3)
}

Sigma Rule

title: CVE-2024-25088 WinDriver Privilege Escalation Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects suspicious IOCTL calls to WinDriver device from non-admin processes
author: Valters IT
date: 2024-01-01
logsource:
    product: windows
    service: sysmon
detection:
    selection:
        EventID: 11  # FileCreate
        TargetFilename|contains: 'windrvr6.sys'
    condition: selection
falsepositives:
    - Legitimate WinDriver updates
level: high

Suricata Rule

alert ip any any -> any any (msg:"CVE-2024-25088 WinDriver Privilege Escalation Attempt"; content:"|5c 00 5c 00 2e 00 5c 00 57 00 69 00 6e 00 44 00 72 00 76 00 72 00 36|"; sid:1000001; rev:1;)

Note: This rule detects the device path \\.\WinDrvr6 in network traffic (unlikely but included for completeness).

Remediation & Mitigation

Immediate Actions:

1. Patch: Upgrade Jungo WinDriver to version 12.5.1 or later. Download from the official Jungo website.
2. Workaround: If patching is not possible, uninstall WinDriver or disable the windrvr6 service via sc stop windrvr6 and sc config windrvr6 start= disabled.
3. Access Control: Restrict local user accounts and enforce least privilege.

Long-Term Measures:

• Implement application whitelisting to block untrusted drivers.
• Regularly audit installed drivers using driverquery /v.
• Monitor for CVEs related to kernel-mode drivers and apply patches promptly.

Valters IT Signature: This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.