On my 18.04 laptop it is group shadow and group readable. If anyone can still reproduce this, please re-open this bug. It is likely an intaller bug.
** Changed in: shadow (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1595080 Title: /etc/shadow has wrong ownership To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1595080/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs