C++ supports developers in object-orientated programming and removes from the developer the responsibility of dealing with many object-oriented programming (OOP) paradigm problems. But these problems do not magically disappear. Rather it is the compiler that aims to provide a solution to many of the complexities that arise from C++ objects, virtual methods, inheritance etc. At its best the solution is almost transparent for the developers. But beware of assuming or relying on ‘under-the-hood’ behavior. This is what I want to share in this post – some aspects of how compilers deal with C++ objects, virtual methods, inheritance, etc. At the end I want to describe a real-world problem that I analyzed recently, which I called a “pointer casting vulnerability”.