Testing your own server's security through simulated attacks can reveal genuine vulnerabilities before real attackers find them — this guide covers the legal/ethical framing and basic approach for testing infrastructure you own.
Important: Only Test What You Own or Have Explicit Authorization For
Penetration testing anything you don't own or lack explicit written authorization to test is illegal in most jurisdictions, regardless of intent — this article covers testing your own VPS specifically; never apply these techniques against systems you don't have clear authorization to test.
What Penetration Testing Involves
Systematically attempting to identify and, with permission, exploit vulnerabilities — going beyond passive vulnerability scanning (see How to Set Up Automated Vulnerability Scanning with OpenVAS) to actually attempt exploitation, confirming whether a theoretical vulnerability is genuinely exploitable in practice.
Basic Reconnaissance
nmap -sV -p- YOUR_SERVER_IPIdentify open ports and running service versions — the starting point for understanding your actual exposed attack surface.
Checking for Known Vulnerabilities in Identified Services
nmap --script vuln YOUR_SERVER_IPNmap's vulnerability scripts check identified services against known vulnerability signatures — a starting point for understanding potential exposure.
Testing Web Application Security
Several open-source web application security testing tools exist for systematically probing your own web applications for common vulnerability classes (see Understanding and Mitigating the OWASP Top 10 Vulnerabilities for the categories these tools typically test against).
Testing SSH Configuration Strength
nmap --script ssh2-enum-algos YOUR_SERVER_IPVerifies your SSH server isn't offering weak/deprecated ciphers or algorithms — see How to Harden SSH Beyond the Basics (Ciphers, MACs & Algorithms) for addressing findings.
Testing for Common Misconfigurations
- Default credentials on any exposed service
- Unnecessarily exposed administrative interfaces
- Overly permissive firewall rules
Using a Dedicated Penetration Testing Distribution (For More Comprehensive Testing)
Specialized Linux distributions bundle many security testing tools together — useful if conducting more thorough, structured testing beyond basic checks; ensure you understand and are authorized to use each specific tool included.
Documenting Findings
Record what you find, its severity, and remediation status — similar structure to How to Conduct a Security Audit of Your VPS, treating penetration testing findings with the same systematic tracking discipline.
When to Consider a Professional Penetration Test
For genuinely critical systems, particularly those handling sensitive data or subject to compliance requirements, a professional third-party penetration test brings expertise and a fresh perspective beyond what self-testing typically achieves — consider this for higher-stakes systems even if you conduct your own basic testing regularly for lower-risk infrastructure.
Testing in a Non-Production Environment When Possible
Some testing techniques can cause service disruption — where feasible, test against a staging/non-production copy of your infrastructure rather than directly against a live production system serving real users.
Remediating Findings
Testing without follow-through provides limited value — treat findings as action items, addressing them systematically (see the broader Security Hardening Checklist for a Production VPS) rather than just documenting and moving on.
Continue Reading
- How to Set Up Automated Vulnerability Scanning with OpenVAS
- How to Conduct a Security Audit of Your VPS
- How to Harden SSH Beyond the Basics (Ciphers, MACs & Algorithms)
Browse more articles in Advanced Security & Compliance.
