Mastering Linux Security and Hardening

adduser on Debian/Ubuntu

The adduser utility is an interactive way to create user accounts and passwords with a single command, which is unique to the Debian family of Linux distros. Most of the default settings that are missing from the Debian implementation of useradd are already set for adduser. The only thing wrong with the default settings is that it creates user home directories with the wide-open 755 permissions value. Fortunately, that's easy to change. (We'll see how in just a bit.)

Although adduser is handy for just casual creation of user accounts, it doesn't offer the flexibility of useradd and it isn't suitable for use in shell scripting. One thing that adduser will do that useradd won't is to automatically encrypt a user's home ...