[icebraining]

On Windows, the equivalent to the X problem was called a Shatter attack: https://en.wikipedia.org/wiki/Shatter_attack

Vista and subsequent reduced the problem by introduce levels, so that lower-privileged applications can't interact with higher-privileged, but as far as I know they can still interact with applications at the same level.

[pjmlp]

That was fixed on Windows 8 and later with all store improvements.

And Microsoft is still quite confident that eventually Win32 will join Win16, even if it takes considerably longer that they were initially willing to wait for.