Security settings and user rights management in Linux systems

With the continuous development of computer technology, the Linux operating system has become one of the most widely used operating systems by enterprises and individuals. Linux not only has the characteristics of efficiency and stability, but also has open source code to achieve better freedom and flexibility. However, in the process of using the Linux operating system on the network, an important issue is the security of the system. This article will focus on the security settings and user rights management in Linux systems to help Linux users better master system management skills.

1. Password settings

A secure password is the basis for system security. Therefore, in Linux systems, special attention needs to be paid to password settings. First, administrators are advised to ensure that each user has a strong password that includes a combination of letters, numbers, and symbols. Second, before assigning passwords to users, make sure all default passwords have been changed and set password expiration times so users can change their passwords regularly.

In addition, in order to strengthen security and improve the ability to resist brute force cracking, it is recommended to increase the security of passwords by limiting the number of login attempts. You can use modules in the PAM library to set account lockout policies or use the fail2ban tool to block brute force attacks.

2. Firewall settings

The built-in firewall tool iptables in the Linux system can well protect the system from network attacks. iptables filters inbound and outbound network traffic based on preset rules. To better protect your system, you need to know exactly which ports are necessary and which ones can be closed.

For example, generally speaking, only ssh (port 22), web server (port 80 and 443) or load balancer (port 8080) need to be open to the outside world. Therefore, you can use iptables to set up a firewall that only allows inbound data flow on these ports. This will effectively reduce the risk of malicious attacks on the system.

3. SELinux settings

SELinux is a mandatory access control mechanism that protects the operating system from various network attacks. The tool restricts access to files and processes by setting various policies, and restricts operations by checking the security context of the process source. For highly sensitive environments, SELinux is required.

In many Linux distributions, SELinux is turned off by default. After SELinux is enabled, various operations in the system will be forced to comply with the rules of the policy package. To better manage SELinux policies, you can use semanage or other tools to manage custom policy modules.

4. User rights management

A good user rights management strategy is an important means to protect system security. The so-called user rights management actually means assigning different rights to different users. For example, administrators can grant root privileges to users with administrator accounts so that they can better manage the system.

In order to achieve fine-grained user rights management, you can use two main concepts in Linux: user (user) and group (group). A user is an individual, while a group is a collection used to aggregate multiple users together. You can use production management tools such as sudo to control user access and limit the privileges of ordinary users.

Also, although getting rid of root operations is a good idea, the necessary task is also psychological. The manually entered command may be correct, but it is not registered to the same license server and may cause irreversible damage to the target system in some cases. Therefore, using the root user in the operating system should be avoided and should Limit the use of the root user to a minimum. In addition, you can also use the command chroot and root tracking functions to restrict the root user's access rights.

In short, the security settings and user rights management of Linux systems are the basis for protecting your system from malicious attacks. To better protect your system, you need to adopt security measures and strategies, such as setting strong passwords, limiting the number of login attempts, setting up firewalls, and enabling SELinux. In addition, you can grant different permissions to different users and groups through user rights management to achieve fine management. This will protect your system and improve system security.

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