What I find pretty funny, is that iTunes is (was? from memory anyway) built with a special flag to the kernel saying "Don't debug me!" which would disallow attempts to ptrace() or otherwise poke ...
So I had to wipe my parents computer running High Sierra and do a clean install of Mojave (there is a Time Machine backup but for now let's call that point moot and iCloud didn't back up the passwords ...
I will start this out by reminding everyone that you should be using a password manager to store and protect all of your passwords. We've reached a point where password managers should be considered ...