Oracle Linux - How to Remove Passwordless Sudo to "root" from "opc" User

Applies to:

Oracle Cloud Infrastructure 

Linux x86-64

Goal:

This document describes how to remove passwordless switch to root from the opc user.

Solution:

You can modify the /etc/sudoers configuration file to enforce password authentication for the "opc" user 

when executing "sudo su -".

IMPORTANT:

1. Ensure you have created a password for the opc user if you are using password authentication in sudo

2. If your system is accessible from the internet for SSH, ensure that the PasswordAuthentication for the SSH service is disabled, otherwise the system could be compromised by a brute-force authentication attack. SSH connectivity should only accept key-based authentication as far as possible.