Linux hardening

This intensive 1‑day training teaches you how to harden a Linux server from the ground up. You’ll learn to minimize the system footprint, lock down user privileges, secure network exposure, and reinforce critical services. Through hands‑on exercises, you’ll apply real‑world hardening techniques used by security professionals.

Download the program (pdf)

Targeted audience:

System administrators
Dev(Sec)Ops engineers

Educational goals:

Identify common entry points, privilege‑escalation paths, and misconfigurations
Minimize installed software and apply kernel and filesystem protections
Configure strong authentication, secure sudo policies, and controlled user environments
Secure network interfaces, firewall rules, and remote access pathways
Deploy logging, auditing, and basic intrusion‑detection mechanisms

Prerequisites:

Being comfortable with CLI mode
Familiarity with basic Linux administration

Program:

Introduction

Why hardening matters?
Understanding the attack surface
Defense in depth
Principle of least privilege
Minimal install philosophy
Hardening is role-specific
Reference frameworks
Baseline vs. hardening vs. compliance

System baseline

Partitioning strategy
Unnecessary packages & services
Unused kernel modules
Hardening the Kernel

Account hardening

Mandatory Access Control (MAC)
Account and sudo hardening
Password and authentication policy

Network hardening

Network exposure
Firewalling
Brute-force mitigation

Services hardening

Dedicated users
File permissions
Service sandboxing

Filesystem, permissions & integrity

SUID/SGID auditing
Sticky bit and ACLs
Immutable attributes
File integrity monitoring

Logging, auditing & monitoring

Kernel-level security event
Centralized logging
Intrusion detection concepts

Automation & compliance validation

Scoring with Lynis
Formal compliance scoring with OpenSCAP
Hardening-as-code with Ansible

Resources

Books
Interactive platforms
Courses & videos
Tools

Gwendal Le Coguic - contact@glc.st - quotes on request - SIRET 79778302400038