If you're debugging as the same user that makes sense because the debugger is supervising the code. (the debugger can't for example halt other processes besides

If you're debugging as the same user that makes sense because the debugger is supervising the code. (the debugger can't for example halt other processes besides the code it's supervising). But how can some other random process even with the same user just inject itself into running compiled code without somehow having the ability to rewrite memory? [edit: memory that has already been allocated by the kernel for the thread it's trying to interfere with]