Why Web Application Penetration Testing and Code Review work best together

Your web application is the face of your business. It’s where your customers log in, make purchases, and share personal information. But every line of code and every integration point is also a potential target for attackers.

As part of our web application tests, we also offer an optional source code review. Not only will testing with application source code result in a much more efficient test. It will also provide the opportunity to detect much more complex issues that typically take a lot longer to find in a normal test.

Aside from the previous benefits, a code review often also speeds up the remediation phase, as issues can be pinpointed exactly in the code. Code maintainers will have more leeway to focus on the detected vulnerability this way, without having to pinpoint the exact lines of code that were impacted.

A secure code review is a structured process where developers and security specialists examine source code to detect:

• Vulnerabilities (e.g., SQL injection, XSS)

• Logic errors and insecure design patterns

• Coding mistakes that could lead to performance or reliability issues

By integrating code review early in the development lifecycle (“shift-left security”), businesses prevent weaknesses before they reach production.

Pentesting is the “real-world attack simulation” for your web app. Ethical hackers look for ways in, testing your app the same way a cybercriminal would. This helps uncover:

• Security flaws that only show up once the app is live

• Weaknesses in authentication, APIs, or server setups

• Misconfigurations that developers might overlook

If code review is the foundation, pentesting is the stress test.

Code review and pentesting are not alternatives. They are two sides of the same coin. Here’s why:

1. Different perspectives, one goal
   • Code review finds vulnerabilities in the design and logic.
   • Pentesting validates whether those vulnerabilities can actually be exploited.
2. Defense in depth
   • Security is strongest when multiple layers overlap. Code review prevents issues at the source, while pentesting ensures nothing slipped through.
3. Cost and risk reduction
   • Fixing issues in code review is cheaper than fixing them post-release.
   • Pentesting ensures compliance and protects against costly breaches.
4. Continuous security
   • Code review integrates security into development.
   • Pentesting keeps applications resilient against evolving threats.