🐧🛡️ Linux Hardening Toolkit

Overview

The Linux Hardening Toolkit is a powerful and easy-to-use script to enhance the security of your Linux systems.
It applies a wide range of best practices for system hardening, service minimization, kernel protection, and package security.

Designed for Debian, Ubuntu, and Fedora systems.

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Features

✅ Harden system configuration (sysctl, limits, permissions)
✅ Install essential security packages (e.g., Firejail, AppArmor, AIDE, Zeek, Suricata)
✅ Disable unnecessary and vulnerable services
✅ Blacklist unused and risky kernel modules
✅ Runs multiple times without conflict
✅ Logging of all operations to /var/log/harden_linux.log
✅ Dry-run mode and Assume-yes automation
✅ Colored terminal output for better readability
✅ Compatible with Ubuntu, Debian, and Fedora

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Requirements

• Bash 4+
• sudo privileges
• Supported Linux distribution:
  • Ubuntu 20.04/22.04+
  • Debian 11+
  • Fedora 36+

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Usage

First, make the script executable:

chmod +x harden_linux.sh

Then, you can run it with different options:

Command Example	Description
sudo ./harden_linux.sh --all --assume-yes	Apply full system hardening automatically
sudo ./harden_linux.sh --install	Only install security-related packages
sudo ./harden_linux.sh --permissions	Only fix system file permissions
sudo ./harden_linux.sh --services	Only disable unnecessary services
sudo ./harden_linux.sh --dry-run --all	Simulate all changes without applying them
./harden_linux.sh --help	Show help message
./harden_linux.sh --version	Display version information

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Important Notes

• Backups: The script automatically backs up critical configuration files before modifying them.
• Dry-Run: Always recommended on production servers before applying changes.
• Logs: All actions are logged to /var/log/harden_linux.log for audit and troubleshooting.