Tips for Hardening FreeBSD to achieve System Protection

Jul 19, 2023 • FreeBSDSoftware

FreeBSD is a powerful, flexible, and cost-effective UNIX-based operating system. While its default installation is secure enough for most uses, there are still several ways to enhance its security even further. This guide will elaborate on various methods to harden and optimize your FreeBSD system for added security.

To start with, the Effective Resource Management guide will provide valuable information on administering your FreeBSD system efficiently.

System Installation

During the installation phase, select the absolute minimum required packages. This reduces the attack surface and consistency simplifies maintenance. Keep in mind that you can always install packages later on, such as nmap, from our FreeBSD Ports as per your requirements.

User Accounts

Avoid using the root account for everyday tasks. Use minimal privilege user accounts for all non-administrative tasks. Implement the principle of least privilege and use sudo for administrative tasks with your regular user account.

Filesystem Protections

System files and directories should have the correct permissions set. Use flags such as nosuid, noexec, and nodev on applicable filesystems. For instance, using the nosuid flag prevents the suid bit on that filesystem, thus negating the risk posed by suid programs.

Also, enable ACLs to set file permissions on a much more granular level. Can be achieved via the setfacl and getfacl commands.


A properly configured firewall is crucial to protect your system. Refer to our guides on Implementing Firewalls for Security and FreeBSD Firewall Configuration for detailed instructions.

System Updates

Make sure your system and all installed packages are regularly updated to their latest versions. This way, you can mitigate the risks posed by known vulnerabilities. Take a look at our Package Management guide for effective package management in FreeBSD.

System Services

Disable unnecessary services to reduce the attack surface. Stick with a minimalist approach, i.e., only run necessary services that are in use.

Password Policies

Implement strong password policies for all user accounts. Use the pam_passwdqc module to enforce complex password rules. Also, use password aging to enforce regular password changes.

Logging and Monitoring

One of the best methods to detect anomalies or intrusions is by extensive logging and monitoring. Check our System Monitoring and Logging guide to learn how it’s done in FreeBSD.

Network Security

There’s a lot to consider when configuring network interfaces. Secure your server by only enabling necessary network services and protocols. For detailed steps, refer to our guides on Configuring Network Interfaces, DHCP Server, and IPv6 Configuration.

Secure Shell (SSH)

Consider disabling root logins and password authentications over SSH. Instead, use key-based logins and employ a strong key pair to maintain a secure connection. Limit SSH access to trusted IP addresses or networks if possible.

Hardening FreeBSD is not an easy task, but it’s certainly worth it for the level of security that can be achieved. Applying these best practices will massively enhance the security of your FreeBSD server. Once hardened, the system becomes much more resistant to various types of attacks, ensuring peace of mind for system administrators. The practices described above go hand in hand with other FreeBSD Best Security Practices.

Remember, security is a continuous process. Regularly audit your system and keep abreast of the latest security issues and updates. Keep learning and improving your FreeBSD system for ultimate protection.

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