The Linux server is the basis of the latest web infrastructure due to reliability, flexibility, and nature through open source. But great responsibility has great power. These systems are often the main goal of cyber directors who play an important role in websites, databases, and applications. Linux server protection is important not only to protect confidential data, but also to maintain suitability for non-polarity time, trust, and security standards. In this guide, we will introduce a demonstrated strategy to take into account the most common threats faced by the Linux server today and provide an effective solution.
1. Common Threats aimed at the Linux Servers
Understanding the threat is the first step in protection. The most common attack on Linux-based systems is:
Brute-Force SSH Attacks:
The attacker uses automated tools to guess SSH login credentials on the system and often aims to access the system.
Malware & Rootkit:
Malware can ruin Linux systems. It is often hidden within core files or running as background processes. Rootkits are more dangerous as they provide persistent root-level access.
Incorrect services:
Misconfigured services can expose a port, allow anonymous access, or provide a simple entrance point to the attacker.
Privilege Escalation:
Even if an attacker approaches unnecessary levels, he often tries to worsen permissions. This is generally achieved due to the vulnerabilities known in outdated packages.
Denial of Services Attack (DOS):
Attacks of DOS or DDoS are characterized by traffic, overwhelming resources, and downtime.
Modify SSH Access
SSH is the most common access method for the Linux server. Implement the following measurements.
Disable the root login:
Modify /etc/ssh/sshd_config to PermitRootLogin no.
Use key-based authentication:
Disable the password login and authenticate the SSH key to increase the safety.
Port Change 22:
Switching to a non-standard port (e.g., 2222) can reduce bot attacks.
Install Fail2ban or SSHGuard:
This tool blocks the IP after several failed login attempts.
Regular Updates and Patch Management
Older software is the main vulnerability. Turn on automatic security updates using package administrators such as apt, yum, or dnf.
Run Periodically:
sudo apt update && sudo apt upgrade
Or
sudo yum update
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Configuring a Firewall
A properly configured Linux Firewall restricts unauthorized access to open ports.
Use ufw for Ubuntu:
sudo ufw allow OpenSSH
sudo ufw enable
On CentOS/RHEL, use firewalld or iptables.
Limit access only to the necessary services and IPs.
Installing and Using Tools to Detect Intrusion
Tools, such as AIDE ( Advanced Intrusion Detection Environment) or OSSEC support, detect unauthorized changes in system files and configuration.
Install AIDE:
sudo apt install aide
sudo aideinit
You should have regular checks with cron jobs to stay ahead of any system compromise.
Monitoring Logs Regularly
The log file provides important information about suspicious activities. You should monitor:
- /var/log/auth.log for login attempts
- /var/log/syslog or /var/log/messages for system errors
- Use logwatch or GoAccess for easier log analysis.
Disable Unnecessary Ports
You should only run the services you actually need. Use netstat, ss, or lsof to check open ports and active services:
sudo netstat -tulpn
Disable the services that you havenβt used With systemctl:
sudo systemctl disable service_name
Safe User Account
- Use a powerful and unique password and enforce password policy with the same tools as pam_pwquality.
- Β Delete the user account you do not use and block the inactive account.
- Β Set the expiration date of temporary users.
- Β You can also use sudo instead of directly accessing Corney.
Safe & Secure File Permission
The authority to access the file must follow the principle of the least privilege. Make sure the web content belongs to the relevant users and cannot be writable to everyone.
chmod 644 file
chmod 755 directory
Protect critical files like:
- /etc/passwd
- /etc/shadow
- /boot
- /etc/ssh/sshd_config
You have to use ls -l and chmod/chown wisely to manage file permissions.
Back Up Regularly
After applying the best security practices, you can still have security issues. Having regular backups ensures recovery. You can automate backups using rsync, tar, or backup software. You should also test backup restoration.
Conclusion
Linux server protection is not a single task. It involves continuous hardening and monitoring. Attackers are developing together as safety practices. From SSH protection to regular updating of the system, each stage plays a decisive role in protecting from unauthorized access and violations. As cyberattacks grow, server safety management becomes an effective technology. To facilitate configuration and supervision, many administrators use web hosting control panels to automate security policies, user management, and monitoring with minimal manual input.
Regardless of whether you use a personal blog or an application for an application, this method helps to keep the Linux server safe, compatible, and sustainable.