Ubuntu Developers made the decision to change model of access to home directories of users in the system. Starting from Ubuntu 21.04, home directories will be created with 750 (drwxr-x —) permissions, restricting access to the directory only to the owner and group members. The necessary changes have already been added to the adduser and shadow packages. The truncated permissions will be set only for new home directories, everything will remain unchanged on previously installed systems.
For historical reasons, user home directories in Ubuntu were created with permissions 755 (drwxr-xr-x), allowing one user to view the contents of another’s directory. Fifteen years ago, this approach was justified by making it easier for users to collaborate (assuming that Ubuntu is mostly used family members or work colleagues who will find it much easier to share files if they have access to each other’s directories). Since then, the scope of Ubuntu has expanded to server systems and in modern realities this approach is perceived as a security problem leading to a violation of privacy.