Ubuntu 21.04 Will Finally Stop Making New Home Directories World-Readable
Creating new users on Ubuntu systems up to now have led to home directories being world-readable. Home directories were created with 755 permissions but will be dropped to 750 now to prevent new home directories from being readable by other users on the system.
Going back to at least 2006 have been complaints over home permissions being too open. The original basis for that world-readable default is on multi-user systems there being "some level of cooperation among the users" and easier to share/access files between users on the same system. But with all the security concerns these days and Ubuntu continuing to focus more on cloud/servers, this default behavior is changing.
With Ubuntu 21.04, newly-created users won't be world-readable but can of course be changed by the user/administrator if desired.
The plan for "private home directories" was originally proposed months ago but now without any complaints, the change is currently in the proposed queue for Ubuntu 21.04. More details on the change via the Ubuntu mailing list.