Yes, processes get their own address space, but there are APIs to read/write the address space of other processes, and on traditional desktop OSes, those APIs a

Yes, processes get their own address space, but there are APIs to read/write the address space of other processes, and on traditional desktop OSes, those APIs are accessible to other processes running as the same user. Virtual address spaces are for a) protection between processes running as different users and b) stability when other processes are incompetent but not malicious. Windows: https://docs.microsoft.com/en-us/windows/desktop/api/memoryapi/nf-memoryapi-readprocessmemory https://docs.microsoft.com/en-us/windows/desktop/api/memorya... macOS (Mach): https://developer.apple.com/documentation/kernel/1402405-mach_vm_read?language=objc https://developer.apple.com/documentation/kernel/1402405-mac... Linux: /proc/*/mem or http://man7.org/linux/man-pages/man2/process_vm_readv.2.html http://man7.org/linux/man-pages/man2/process_vm_readv.2.html and so forth.