White Box Penetration Testing

Source Code Makes the Difference

Black-box testing shows you what an external attacker can find. White-box testing shows you everything else. With full access to your source code, architecture diagrams, and internal documentation, our consultants trace vulnerabilities from the code path to the exploit – catching flaws that no scanner or black-box test would surface.

Every white-box engagement is led by OSWE-certified consultants who read code daily. We manually review authentication logic, cryptographic implementations, input validation, authorisation checks, and business logic – then prove each finding with a working exploit.

What We Review

Authentication and Session Management: Token generation, session handling, password storage, OAuth flows, and MFA implementation.
Authorisation and Access Controls: Role-based access, object-level permissions, privilege escalation paths, and IDOR vulnerabilities at the code level.
Input Handling and Injection: SQL injection, command injection, SSTI, deserialisation, and any path where user input reaches a sensitive sink.
Cryptographic Implementation: Key management, encryption algorithms, hashing schemes, and random number generation.
Business Logic: Payment flows, state machine transitions, race conditions, and any workflow where the intended sequence can be broken.
Third-Party Dependencies: Known vulnerable libraries, insecure configurations, and supply chain risks in your dependency tree.

Why FORTBRIDGE?

We don’t just flag findings in a report. Our consultants sit down with your developers, walk through the vulnerable code paths, and work together on fixes. We verify the remediation and re-test to confirm the issue is resolved. That hands-on approach is why clients come back to us engagement after engagement.

OSWE-Certified Reviewers: Our consultants hold the Offensive Security Web Expert certification – they exploit web applications through source code analysis as part of the exam itself.
Language Agnostic: We review code across Java, C#/.NET, Python, PHP, Node.js, Go, Ruby, and more.
Senior-Only Engagements: Every review is led by consultants with 10-20 years of offensive experience. No juniors, no padding.
Developer-Friendly Reporting: Findings include the exact file, function, and line number – plus a working proof of concept and clear remediation steps.

When to Choose White Box Over Black Box

White-box testing gives the deepest coverage. Choose it when you want maximum assurance – before a major release, after a significant refactor, for compliance with standards like PCI DSS or SOC 2, or when a previous black-box test has already been done and you want to go deeper. It’s also the right choice for security-critical applications where the cost of a missed vulnerability is high.