In the Ubuntu operating system, the root user is the user with the highest authority and can perform all operations on the system. However, by default, Ubuntu disables the root user and instead uses the sudo command for administrator privileges. This article will detail how to set up and manage root user privileges in Ubuntu, and discuss some common security risks and precautions.
What is the root user?
The root user refers to the user with the highest authority in the Linux system. Unlike other users, the root user can perform all operations on the system and has access to all files and directories. Therefore, the root user is very important, but at the same time, it is very dangerous, and if it is hacked or mishandled, it may lead to serious consequences.
How to enable root user
In Ubuntu, the root user is disabled by default. However, we can enable the root user in two ways:
1. Use the sudo command
The sudo command is a common way to control administrator privileges in Ubuntu. It allows normal users to execute certain commands with root privileges. Through the sudo command, we can avoid using the root user to log in to the system, thereby improving the security of the system.
To use the sudo command, the user needs to be added to the sudo group. The current user can be added to the sudo group with the following command:
$ sudo usermod -aG sudo username
Among them, username is the username to be added.
After the addition is successful, you can use the following command to execute a command with sudo privileges:
$ sudo command
For example, to install a package with sudo privileges:
$ sudo apt-get install package-name
2. Enable root user
If you need to use the root user to log in to the system directly, you can enable the root user with the following command:
$ sudo passwd root
Then enter the current user password and set the password for the root user. After the setting is successful, you can log in to the system as the root user.
How to disable root user?
In order to improve the security of the system, in daily operation and maintenance, we should not directly use the root user to log in to the system, but should use the sudo command to perform administrator operations. If you really need to disable the root user, you can do it with the following command:
$ sudo passwd -l root
This command locks the root user and prevents him from logging into the system. If you need to unlock it, you can use the following command:
$ sudo passwd -u root
Security Risks and Precautions
Although the root user has the highest authority, it also poses a great security risk. Unauthorized access, malware infection, misuse, etc. can lead to loss or corruption of system data. Therefore, when using the root user, you must pay attention to the following points:
1. Do not abuse root privileges
Try to avoid using root privileges unnecessarily and only when necessary. For some common operations, the sudo command should be used.
2. Change your password regularly
To avoid password leaks, you should change the password of the root user regularly, and use a strong password policy, including using combinations of characters such as numbers, letters, and symbols.
3. Avoid opening the SSH port
SSH is a commonly used remote login protocol in Linux systems. However, if you open the SSH port to the external network, you will face a great security risk. Therefore, when using the SSH protocol, key authentication should be used, and the SSH port should be limited to the LAN.
4. Back up data regularly
No matter how secure a system is, it is difficult to completely avoid the risk of data loss or corruption. Therefore, the system and important data should be backed up regularly to prevent data loss.
5. Install security software
In the Linux system, some security software can be installed to improve the security of the system. For example, firewall software, intrusion detection system and other software can be installed to enhance the security of the system.
Summarize
The root user is the user with the highest authority in the Ubuntu operating system and can perform all operations on the system. By default, Ubuntu disables the root user and uses the sudo command for administrator privileges. If you need to use the root user directly, you can use the command to enable it. But at the same time, the root user also has a great security risk. You need to pay attention to the following precautions: do not abuse root privileges, change passwords regularly, avoid opening SSH ports, back up data regularly, and install security software. Through these measures, the security of the system can be improved, and the security and integrity of the system data can be protected.