Most of these problems come down to Windows has IPCs (interprocess communications), procedures that move information from one program to another, that were never designed with security in mind. Windows and Windows applications rely on these procedures to get work done. Over the years they've included DLLs (dynamic link libraries), OCXs (Object Linking and Embedding (OLE) Control Extension), and ActiveX. No matter what they're called, they do the same kind of work and they do it without any regard to security.
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