Linux Security Mastery
@amitmund
July 09, 2026
Linux Security Mastery
The Complete Beginner to Advanced Guide to Linux Security, System Hardening, Kernel Security, Identity & Access Management, Cryptography, Network Security, Container Security, Cloud Security, Detection Engineering, Incident Response, and Enterprise Security Architecture
Course Goal
This course is designed to take you from absolute beginner to production-ready Linux Security Engineer, DevSecOps Engineer, Cloud Security Engineer, Platform Security Engineer, SRE, Security Architect, or Distinguished Infrastructure Engineer.
By the end of this learning track, you will be able to:
- Master Linux security architecture
- Secure Linux servers from kernel to application
- Understand Linux authentication and authorization
- Implement enterprise security hardening
- Secure Docker and Kubernetes workloads
- Build Zero Trust Linux infrastructures
- Perform security auditing and incident response
- Detect and investigate attacks
- Design secure production architectures
- Prepare for Linux Security, DevSecOps, Cloud Security, and System Design interviews
Prerequisites
- Linux Mastery
- Linux Networking Mastery
- Bash Scripting Mastery
- Networking Fundamentals
- Basic Cryptography
- Docker (Recommended)
- Kubernetes (Recommended)
Course Structure
Module 1 — Linux Security Fundamentals
Chapter 1 — Introduction to Linux Security
- Security Principles
- CIA Triad
- Defense in Depth
- Threat Landscape
- Security Models
- Linux Security Architecture
- Common Attack Vectors
Chapter 2 — Linux Security Architecture
- User Space
- Kernel Space
- Trusted Computing Base
- Security Boundaries
- Privilege Separation
Chapter 3 — Linux Boot Security
- BIOS
- UEFI
- Secure Boot
- TPM
- Measured Boot
- Boot Chain Verification
Chapter 4 — Linux Threat Modeling
- STRIDE
- DREAD
- Attack Trees
- Kill Chain
- MITRE ATT&CK
Module 2 — Authentication & Authorization
Chapter 5 — Linux Users & Groups
Chapter 6 — UID & GID
Chapter 7 — PAM (Pluggable Authentication Modules)
Chapter 8 — NSS (Name Service Switch)
Chapter 9 — Sudo
Chapter 10 — sudoers
Chapter 11 — Polkit
Chapter 12 — RBAC
Chapter 13 — LDAP
Chapter 14 — Active Directory Integration
Chapter 15 — Kerberos
Chapter 16 — Multi-Factor Authentication (MFA)
Module 3 — File System Security
Chapter 17 — Linux Permissions
Chapter 18 — chmod
Chapter 19 — chown
Chapter 20 — ACLs
Chapter 21 — Extended Attributes
Chapter 22 — Immutable Files
Chapter 23 — File Integrity Monitoring
Chapter 24 — Filesystem Encryption
Module 4 — Process Security
Chapter 25 — Process Isolation
Chapter 26 — Capabilities
Chapter 27 — Namespaces
Chapter 28 — cgroups
Chapter 29 — seccomp
Chapter 30 — AppArmor
Chapter 31 — SELinux
Chapter 32 — Landlock LSM
Module 5 — Linux Kernel Security
Chapter 33 — Linux Security Modules (LSM)
Chapter 34 — Kernel Hardening
Chapter 35 — Kernel Lockdown
Chapter 36 — ASLR
Chapter 37 — Stack Protection
Chapter 38 — Memory Protection
Chapter 39 — Kernel Exploits
Chapter 40 — Kernel Mitigations
Module 6 — Network Security
Chapter 41 — Netfilter
Chapter 42 — iptables
Chapter 43 — nftables
Chapter 44 — firewalld
Chapter 45 — TCP Security
Chapter 46 — Port Knocking
Chapter 47 — VPN
Chapter 48 — WireGuard
Chapter 49 — SSH Hardening
Chapter 50 — IDS/IPS
Module 7 — Cryptography
Chapter 51 — Cryptography Fundamentals
Chapter 52 — Hashing
Chapter 53 — Symmetric Encryption
Chapter 54 — Asymmetric Encryption
Chapter 55 — PKI
Chapter 56 — Certificates
Chapter 57 — TLS
Chapter 58 — OpenSSL
Chapter 59 — GPG
Chapter 60 — Disk Encryption
Module 8 — Secrets Management
Chapter 61 — Password Management
Chapter 62 — HashiCorp Vault
Chapter 63 — AWS Secrets Manager
Chapter 64 — Azure Key Vault
Chapter 65 — GCP Secret Manager
Chapter 66 — SOPS
Chapter 67 — Environment Variables
Module 9 — Linux Hardening
Chapter 68 — CIS Benchmarks
Chapter 69 — STIG
Chapter 70 — Lynis
Chapter 71 — OpenSCAP
Chapter 72 — Auditd
Chapter 73 — Systemd Hardening
Chapter 74 — Kernel sysctl Hardening
Module 10 — Logging & Auditing
Chapter 75 — syslog
Chapter 76 — journald
Chapter 77 — auditd
Chapter 78 — OSQuery
Chapter 79 — Falco
Chapter 80 — SIEM Integration
Module 11 — Malware & Threat Detection
Chapter 81 — Rootkits
Chapter 82 — Malware Detection
Chapter 83 — ClamAV
Chapter 84 — YARA
Chapter 85 — Sigma Rules
Chapter 86 — Threat Hunting
Module 12 — Container Security
Chapter 87 — Docker Security
Chapter 88 — Image Scanning
Chapter 89 — Runtime Security
Chapter 90 — Trivy
Chapter 91 — Docker Bench
Chapter 92 — Rootless Containers
Module 13 — Kubernetes Security
Chapter 93 — Pod Security
Chapter 94 — Network Policies
Chapter 95 — RBAC
Chapter 96 — Admission Controllers
Chapter 97 — Secrets
Chapter 98 — OPA Gatekeeper
Chapter 99 — Kyverno
Chapter 100 — Runtime Security
Module 14 — Cloud Security
Chapter 101 — AWS Security
Chapter 102 — Azure Security
Chapter 103 — GCP Security
Chapter 104 — IAM
Chapter 105 — Cloud Network Security
Chapter 106 — Security Groups
Chapter 107 — CloudTrail & Audit Logs
Module 15 — DevSecOps
Chapter 108 — Secure SDLC
Chapter 109 — SAST
Chapter 110 — DAST
Chapter 111 — Dependency Scanning
Chapter 112 — Secret Scanning
Chapter 113 — Supply Chain Security
Chapter 114 — SBOM
Chapter 115 — Sigstore
Module 16 — Incident Response
Chapter 116 — Incident Response Lifecycle
Chapter 117 — Digital Forensics
Chapter 118 — Memory Analysis
Chapter 119 — Disk Forensics
Chapter 120 — Log Analysis
Chapter 121 — Malware Analysis
Chapter 122 — Postmortems
Module 17 — Observability & Monitoring
Chapter 123 — Prometheus
Chapter 124 — Grafana
Chapter 125 — Loki
Chapter 126 — OpenTelemetry
Chapter 127 — Security Dashboards
Module 18 — Performance vs Security
Chapter 128 — Secure Performance Tuning
Chapter 129 — eBPF Security
Chapter 130 — XDP Security
Chapter 131 — Secure Kernel Performance
Module 19 — Enterprise Security Architecture
Chapter 132 — Zero Trust
Chapter 133 — Defense in Depth
Chapter 134 — Identity-Centric Security
Chapter 135 — Secure Architecture Patterns
Chapter 136 — High Availability Security
Module 20 — Advanced Linux Security
Chapter 137 — TPM
Chapter 138 — Hardware Security Modules
Chapter 139 — Secure Enclaves
Chapter 140 — Confidential Computing
Chapter 141 — Secure Boot Chain
Chapter 142 — Trusted Execution Environments
Module 21 — Compliance & Governance
Chapter 143 — ISO 27001
Chapter 144 — NIST
Chapter 145 — PCI-DSS
Chapter 146 — HIPAA
Chapter 147 — SOC 2
Chapter 148 — GDPR
Module 22 — Production Security
Chapter 149 — Bastion Hosts
Chapter 150 — Secure Web Servers
Chapter 151 — Database Security
Chapter 152 — Production Hardening
Chapter 153 — Enterprise Linux Security
Chapter 154 — Multi-Cloud Security
Module 23 — Troubleshooting
Chapter 155 — Authentication Issues
Chapter 156 — SELinux Troubleshooting
Chapter 157 — Firewall Problems
Chapter 158 — TLS Debugging
Chapter 159 — Security Incident Investigation
Chapter 160 — Performance Impact Analysis
Module 24 — Interview Preparation
Chapter 161 — Linux Security Interview Questions
Chapter 162 — DevSecOps Interview Questions
Chapter 163 — Cloud Security Interview Questions
Chapter 164 — Kubernetes Security Interview Questions
Chapter 165 — Mock Interviews
Module 25 — Bonus
Chapter 166 — Security Best Practices
Chapter 167 — Common Security Mistakes
Chapter 168 — Security Checklists
Chapter 169 — Linux Security Cheat Sheet
Chapter 170 — Future of Linux Security
Commands Covered
User & Authentication
- passwd
- useradd
- usermod
- groupadd
- sudo
- visudo
- chage
- faillock
Permissions
- chmod
- chown
- chgrp
- getfacl
- setfacl
- lsattr
- chattr
Security
- sestatus
- semanage
- restorecon
- aa-status
- auditctl
- ausearch
- aureport
- lynis
- openscap
Cryptography
- openssl
- gpg
- ssh-keygen
Networking
- ssh
- iptables
- nft
- firewall-cmd
- tcpdump
Monitoring
- journalctl
- syslog
- osqueryi
- falco
- trivy
Technologies Covered
Linux Security
- SELinux
- AppArmor
- seccomp
- Landlock
- Linux Security Modules (LSM)
- auditd
- PAM
- NSS
Networking Security
- iptables
- nftables
- WireGuard
- OpenVPN
- SSH
- Netfilter
Cryptography
- OpenSSL
- GPG
- PKI
- TLS
- X.509
Containers
- Docker
- containerd
- Podman
- Trivy
- Falco
Kubernetes
- OPA Gatekeeper
- Kyverno
- Falco
- Cilium
- Network Policies
Cloud
- AWS IAM
- Azure Entra ID
- GCP IAM
- AWS KMS
- Azure Key Vault
- GCP Secret Manager
Every Chapter Includes
Every chapter follows the same professional learning structure:
- Learning Objectives
- Theory
- Internal Working
- Linux Kernel Security Internals
- Authentication Flow
- Authorization Flow
- Security Architecture
- Threat Models
- Attack Flow Diagrams
- Defense Diagrams
- Mermaid Diagrams
- ASCII Diagrams
- Flowcharts
- Command Reference
- Configuration Examples
- Docker Examples
- Kubernetes Examples
- AWS/Azure/GCP Examples
- Security Hardening Guides
- Production Case Studies
- Security Best Practices
- Performance Considerations
- Common Mistakes
- Troubleshooting Guide
- Detection Engineering Examples
- Threat Hunting Exercises
- Hands-on Labs
- Mini Projects
- Capstone Projects
- Exercises
- Quiz
- Interview Questions
- Cheat Sheet
- Summary
- References
- CIS Benchmarks
- NIST References
- MITRE ATT&CK Mapping
- Further Reading
Hands-on Labs
- Harden a Fresh Linux Installation
- Configure PAM Authentication
- Secure SSH with MFA
- Configure SELinux Policies
- Build an nftables Firewall
- Deploy WireGuard VPN
- Encrypt a Linux Filesystem
- Configure HashiCorp Vault
- Scan Containers with Trivy
- Secure a Kubernetes Cluster
- Detect Runtime Threats with Falco
- Build a SIEM Pipeline
- Perform Incident Response on a Compromised Server
- Apply CIS Benchmark Hardening
- Build a Zero Trust Linux Environment
Capstone Projects
- Enterprise Linux Hardening Toolkit
- Secure Bastion Host
- Zero Trust Linux Platform
- Production Kubernetes Security Platform
- Cloud Security Baseline
- DevSecOps CI/CD Pipeline
- Linux Threat Detection Platform
- Secure Multi-Cloud Infrastructure
- Enterprise Secrets Management Platform
- Linux Security Operations Center (SOC) Lab
Research & Documentation
Study and analyze:
- Linux Kernel Security Documentation
- SELinux Project Documentation
- AppArmor Documentation
- OpenSCAP Documentation
- CIS Linux Benchmarks
- NIST Cybersecurity Framework
- MITRE ATT&CK Framework
- OWASP Top 10
- Kubernetes Security Documentation
- HashiCorp Vault Documentation
- OpenSSL Documentation
Estimated Course Size
- 25 Modules
- 170 Chapters
- 7,500+ Pages
- 3,500+ Command Examples
- 1,500+ Security Architecture & Attack Flow Diagrams
- 600+ Hands-on Labs
- 200+ Production Security Scenarios
- Complete Linux Security, DevSecOps, Cloud Security & Enterprise Security Interview Preparation
Final Outcome
After completing this learning track, you will be able to:
- Secure Linux systems from the bootloader to user-space applications.
- Design and implement enterprise-grade Linux security architectures.
- Harden Linux servers, containers, Kubernetes clusters, and cloud workloads using industry best practices.
- Detect, investigate, and respond to security incidents with modern observability and forensic tools.
- Integrate security into DevOps pipelines through automated scanning, policy enforcement, and supply chain protection.
- Confidently perform the responsibilities of a Linux Security Engineer, DevSecOps Engineer, Platform Security Engineer, Security Architect, or Distinguished Infrastructure Engineer.
- Successfully prepare for advanced Linux Security, Cloud Security, DevSecOps, and System Design interviews.