Security fundamentals

What is penetration testing?

A penetration test is an authorized, simulated attack on your systems by a skilled tester who tries to exploit weaknesses the way a real attacker would, to find and prove exploitable vulnerabilities before someone malicious does.

Definition

Penetration testing (a pen test) is an authorized, simulated cyberattack against your applications, networks, or systems, performed by a skilled tester who actively attempts to exploit vulnerabilities to demonstrate real, exploitable risk.

Background

Automated vulnerability scans find known issues quickly but cannot judge whether an issue is truly exploitable or chain several weaknesses into a real breach. A penetration test adds human expertise: the tester reasons like an attacker, validates findings, and reports the actual business impact. Tests vary by scope (external network, internal network, web application, cloud, social engineering) and by knowledge given to the tester (black box, gray box, white box).

Why it matters

A penetration test tells you which weaknesses a real attacker could actually use, prioritized by impact, rather than a long list of theoretical findings. Auditors and enterprise customers frequently expect one, and it is a practical way to validate that your defenses hold up.

Step by step

1. Define scope and rules of engagement (what is in scope, when, and how).
2. Choose the test type and how much information to share with the tester.
3. Run the test with an authorized, qualified provider.
4. Triage findings by real risk and assign owners and due dates for remediation.
5. Fix the issues and, where warranted, retest to confirm they are resolved.

Examples

• A web-application pen test uncovers a chain of flaws that together allow access to another tenant’s data, a finding a scanner alone would miss.
• A company runs an external network test annually and an application test after each major release.

Common mistakes

• Confusing a vulnerability scan with a penetration test; they are different activities at different depths.
• Testing once and never remediating or retesting the findings.
• Scoping so narrowly that the most important systems are never actually tested.

FAQ