How To Secure A Linux Server
An evolving how-to guide for securing a Linux server that, hopefully, also teaches you a little about security and why it matters. Table of Contents: - Introduction - Guide Objective - Why Secure Your Server - Why Yet Another Guide - Other Guides - To Do / To Add - Guide Overview - About This Guide - My Use-Case - Editing Configuration Files - For The Lazy - Contributing - Before You Start - Identify Your Principles - Picking A Linux Distribution - Installing Linux Pre/Post Installation Requirements - Other Important Notes - Using Ansible Playbooks to secure your Linux Server - The SSH Server - Important Note Before You Make SSH Changes - SSH Public/Private Keys - Create SSH Group For AllowGroups - Secure /etc/ssh/sshd_config - Remove Short Diffie-Hellman Keys - 2FA/MFA for SSH - The Basics - Limit Who Can Use sudo - Limit Who Can Use su - Run applications in a sandbox with FireJail - NTP Client - Securing /proc - Force Accounts To Use Secure Passwords - Automatic Security Updates and Alerts - More Secure Random Entropy Pool (WIP) - Add Panic/Secondary/Fake password Login Security System - The Network Firewall With UFW (Uncomplicated Firewall) - iptables - Intrusion Detection And Prevention with PSAD - Application Intrusion Detection
FEATURES
ALTERNATIVES
Collection of cybersecurity conference videos from GreHack 2018 covering various cutting-edge topics.
A comprehensive guide to using Metasploit, including searching for modules, specifying exploits and payloads, and using auxiliary modules.
Blue-team capture the flag competition for improving cybersecurity skills.
Enhance the security and privacy of Apple silicon Mac computers with incremental changes and user capability.
A comprehensive guide for using Docker with detailed information on prerequisites, installation, containers, images, networks, and more.
A comprehensive guide to network security monitoring, teaching readers how to detect and respond to intrusions using open source software and vendor-neutral tools.
PINNED
Mandos Brief Newsletter
A weekly newsletter providing cybersecurity leadership insights, industry updates, and strategic guidance for security professionals advancing to management positions.
PTJunior
An AI-powered penetration testing platform that autonomously discovers, exploits, and documents vulnerabilities while generating NIST-compliant reports.
CTIChef.com Detection Feeds
A tiered cyber threat intelligence service providing detection rules from public repositories with varying levels of analysis, processing, and guidance for security teams.
ImmuniWeb® Discovery
ImmuniWeb Discovery is an attack surface management platform that continuously monitors an organization's external digital assets for security vulnerabilities, misconfigurations, and threats across domains, applications, cloud resources, and the dark web.
Checkmarx SCA
A software composition analysis tool that identifies vulnerabilities, malicious code, and license risks in open source dependencies throughout the software development lifecycle.
Orca Security
A cloud-native application protection platform that provides agentless security monitoring, vulnerability management, and compliance capabilities across multi-cloud environments.
DryRun
A GitHub application that performs automated security code reviews by analyzing contextual security aspects of code changes during pull requests.