Strategy & Process

What Is Security Testing?

Security testing is the process of identifying vulnerabilities, threats, and risks in a software application to ensure that data and resources are protected from potential attacks and unauthorized access.

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In Depth

Security testing evaluates whether an application properly handles authentication, authorization, data protection, input validation, and communication security. The OWASP Top 10 provides a standard reference for the most critical web application security risks.

Types of security testing include: Static Application Security Testing (SAST) — analyzing source code for vulnerabilities without executing the application; Dynamic Application Security Testing (DAST) — testing the running application by sending malicious inputs; penetration testing — simulating real attacks to find exploitable vulnerabilities; and security code review — manual inspection of code for security flaws.

For QA engineers, security testing means: verifying that authentication works correctly (login, session management, token expiration), checking authorization (users cannot access others' data), testing input validation (SQL injection, XSS prevention), verifying API security (authentication headers, rate limiting), and ensuring sensitive data is not exposed in logs or error messages.

You do not need to be a security specialist. But understanding basic security testing principles and being able to include security checks in your test suites makes you significantly more valuable.

Why Interviewers Ask About This

Security testing is increasingly expected of QA engineers, especially at companies handling sensitive data (finance, healthcare, e-commerce). Interviewers may ask about OWASP Top 10 and how you include security in your testing approach.

Example Scenario

During API testing, a QA engineer discovers that changing the user ID in a GET request returns another user's data — an IDOR (Insecure Direct Object Reference) vulnerability. This is caught before production by adding authorization checks to the API test suite. The fix prevents a potential data breach.

Interview Tip

Know the OWASP Top 10 at a high level. Be able to explain common vulnerabilities like XSS, SQL injection, and IDOR. Discuss how you incorporate security checks into functional testing rather than treating security as a separate phase.