Penetration testing and vulnerability scanning answer different questions

A vulnerability scan and a penetration test provide different evidence. The decision should start with the question the organisation needs to answer. NIST SP 800-115 discusses assessment techniques and their benefits and limitations.

What a scan provides

An automated scan helps identify potential weaknesses across a defined set of assets and configurations. It can provide a repeatable baseline for tracking changes and prioritising validation. Findings need context: an alert does not always demonstrate a viable exploit.

Coverage depends on the tool, credentials, reachable assets and enabled checks. Record what remained outside the assessment.

What a penetration test provides

A penetration test combines evaluator judgement and tools to investigate attack paths within an authorised scope. It can examine whether a weakness permits a specific action or whether findings are connected. Results remain limited by available time, access and agreed rules.

The OWASP Web Security Testing Guide covers techniques for reviewing areas such as configuration, access and application logic. Automated checks and manual evaluation can complement each other.

Compare objectives

Agree the scope first

Document permitted systems, exclusions, test windows, escalation contacts and stop conditions. Third-party services require their own authorisation.

For example, permission to assess an application does not automatically permit testing its identity provider.

Turn findings into improvements

Request evidence, contextualised impact, limitations and practical recommendations. Assign owners and criteria for verifying fixes. Assessment frequency should reflect risk, changes and applicable obligations.

Explore our Cybersecurity approach to define an assessment with clear objectives and deliverables.