Comment 3 for bug 1402036

In Xubuntu 15.04 it happens too and i get messages in /var/log/auth.log :

1. Putting user's password:

Apr 25 11:29:08 Mymachine1 sudo: user1 : user NOT in sudoers ; TTY=pts/7 ; PWD=/u01/home/user1 ; USER=root ; COMMAND=/bin/true

2. Putting root's password:

Apr 25 11:29:21 Mymachine1 sudo: pam_unix(sudo:auth): authentication failure; logname= uid=1003 euid=0 tty=/dev/pts/7 ruser=user1 rhost= user=user1
Apr 25 11:29:23 Mymachine1 sudo: pam_unix(sudo:auth): conversation failed
Apr 25 11:29:23 Mymachine1 sudo: pam_unix(sudo:auth): auth could not identify password for [user1]
Apr 25 11:29:23 Mymachine1 sudo: user1 : user NOT in sudoers ; TTY=pts/7 ; PWD=/u01/home/user1 ; USER=root ; COMMAND=/bin/true

Ask: Do we need all machine users belong to "sudoers" group to permit to change their own personal details ? Why ?