I have a user user1 that is not in the sudoers file (nor belonging to groups in sudoer) but can still use sudo. How is it possible ?
user1~$ groups user1 www-data
My sudoer conf
root ALL=(ALL) ALL %sudo ALL=(ALL) ALL #includedir /etc/sudoers.d user1~$ sudo -l User user1 may run the following commands on this host: (ALL) ALL