Hardening Concepts
Summary
PDF p.247Hardening involves changing default settings of network equipment, software, and operating systems to improve security.
In plain words
Supplementary — not from your PDFHardening means changing insecure, well-known defaults. On switches and routers: change default credentials, disable unused services, use SSH and HTTPS instead of Telnet and HTTP, apply ACLs, turn on logging, use port security, enforce strong passwords, and lock the equipment away. On servers: the same basics, plus regular patching, least privilege, host firewalls and IDS, baselines (CIS/STIG), MFA and PAM, and antimalware.
Detailed explanation
PDF p.247- Default Configurations: Often insecure and well-documented, making them targets for attackers.
- Hardening Methods: Implementing secure baseline recommendations to enhance security.
Switches and Routers
- Change Default Credentials: Prevents unauthorized access.
- Disable Unnecessary Services: Reduces attack surface.
- Use Secure Management Protocols: SSH instead of Telnet, HTTPS instead of HTTP.
- Implement Access Control Lists (ACLs): Restricts access to necessary devices and networks.
- Enable Logging and Monitoring: Identifies issues like repeated login failures.
- Configure Port Security: Limits devices connecting to switch ports.
- Strong Password Policies: Reduces risk of password attacks.
- Physically Secure Equipment: Prevents unauthorized physical access.
Server Hardware and Operating Systems
- Change Default Credentials: Similar to network devices.
- Disable Unnecessary Services: Reduces attack surface.
- Apply Security Patches and Updates Regularly: Fixes vulnerabilities.
- Least Privilege Principle: Limits user privileges to necessary functions.
- Use Firewalls and IDS: Blocks or alerts on malicious activity.
- Secure Configuration: Uses baseline configurations like CIS or STIGs.
- Strong Access Controls: Includes strong password policies, MFA, and PAM.
- Enable Logging and Monitoring: Identifies issues like repeated login failures.
- Use Antivirus and Antimalware Solutions: Detects and quarantines malware.
- Physical Security: Secures server equipment to prevent unauthorized access.
Important terms
taken from the text above- Default Configurations
- Often insecure and well-documented, making them targets for attackers.
- Hardening Methods
- Implementing secure baseline recommendations to enhance security.
- Change Default Credentials
- Prevents unauthorized access.
- Disable Unnecessary Services
- Reduces attack surface.
- Use Secure Management Protocols
- SSH instead of Telnet, HTTPS instead of HTTP.
- Implement Access Control Lists (ACLs)
- Restricts access to necessary devices and networks.
- Enable Logging and Monitoring
- Identifies issues like repeated login failures.
- Configure Port Security
- Limits devices connecting to switch ports.
- Strong Password Policies
- Reduces risk of password attacks.
- Physically Secure Equipment
- Prevents unauthorized physical access.
- Apply Security Patches and Updates Regularly
- Fixes vulnerabilities.
- Least Privilege Principle
- Limits user privileges to necessary functions.
- Use Firewalls and IDS
- Blocks or alerts on malicious activity.
- Secure Configuration
- Uses baseline configurations like CIS or STIGs.
- Strong Access Controls
- Includes strong password policies, MFA, and PAM.
- Use Antivirus and Antimalware Solutions
- Detects and quarantines malware.
- Physical Security
- Secures server equipment to prevent unauthorized access.
Examples & real-world scenarios
Supplementary — not from your PDF- Disabling Telnet on a switch and enabling SSH only.
- Removing unused server roles and services.
- Enabling alerts for repeated failed logins.
Scenario
A new router arrives with Telnet management enabled and a default password. Hardening it before deployment (SSH only, new strong credentials, management restricted to the admin VLAN) closes the easy doors.
Common mistakes
Supplementary — not from your PDF- Leaving management interfaces open to every network.
- Hardening once and never patching afterwards.
Practical skills
Supplementary — not from your PDF- Write a hardening checklist for a switch and a server.
- Harden a VM in your own lab and verify each change.
What I should remember
Key Points PDF p.247The PDF has no Key Points for this subsection. Use the Summary and Detailed Explanation above.