White box

Source code audit: security from the inside

A pentest tests your application from the outside, as an attacker would. A code audit looks at it from the inside, with the code in front of it, and that is where what cannot be seen from the outside appears: a credential hidden between the lines, a missing validation, a logic branch that almost no one ever runs. We read your code to find the flaws at their source, combining the sweep of a tool with the judgement of someone who knows how to read between the lines.

Static analysis, without running your application or touching production. Across Spain.

Why

Reading the code finds what attacking it does not

Attacking an application from the outside only uncovers what the attacker can reach. Reading the code sees everything, even the paths that almost never run, and gets to the root of the problem.

Sees every path

An external attack only walks what it finds. The audit follows every flow in the code, including the ones that rarely run.

Gets to the root cause

It does not stop at the symptom: it points to the exact line and the reason for the flaw, to fix it properly and not with a patch.

Without touching production

The analysis is static: the code is read, not run. Zero impact on your environments and your real data.

Catches what the pentest does not

Secrets written into the code, broken business logic, insecure dead code. Things that are invisible from the outside.

What we find

The flaws that live in the code

We look for both the classic security flaws and the bad development practices that, sooner or later, end up as a hole. These are the fronts where they appear most.

Secrets in the code

Passwords, API keys and tokens written directly into the code, one of the most common and most avoidable leaks.

Injection and validation

Inputs that reach a query or a command unfiltered, the root of SQL injection and of many other problems.

Access control

Permission and authentication checks done badly, which let a user get where they should not.

Misused cryptography

Obsolete algorithms, poorly managed keys or encryption applied where it does not belong, giving a false sense of security.

Vulnerable dependencies

Third party libraries with known flaws, the software supply chain flank, through composition analysis.

Business logic

Errors in how your application works that no tool detects, because they only show up by understanding what it should do.

How

The tool sweeps, the expert understands

Neither machine alone nor hands alone. The two layers need each other: one covers the ground, the other gives it meaning.

The automated analysis

With static analysis (SAST) we sweep through all your code quickly, without leaving a corner, and with composition analysis we review your dependencies for vulnerable versions. That is the breadth: covering all the ground in little time.

The manual review

Then an expert reviews the findings by hand: discarding the false positives that every tool produces, confirming what really matters and understanding your business logic to find what no machine sees alone. That is the depth.

What you take away

Safer code and the path to get there

Not a dump of warnings from a tool, but confirmed findings, prioritized and with the fix alongside.

Findings with their root cause

Each problem with the exact line, the reason and its severity, already filtered of false positives.

Secrets to rotate now

The credentials and keys that live in the code, to get them out of there and change them as soon as possible.

Dependencies to update

The third party libraries with known flaws and which version it is best to move up to.

The fix, not just the warning

Alongside each finding, how to correct it, so your team does not have to investigate from scratch.

Real priority

The findings ordered by risk, so you start with what can really cost you dearly.

Evidence for compliance

The proof that you review the security of your software, useful for the CRA and for your certification.

When

The sooner, the cheaper

A flaw costs little to fix when it has just been written, and a lot when it is already in production. That is why a code audit pays off more the earlier it comes in.

Before going to production

Reviewing the code before launch avoids going live with a hole that is then much more expensive to close.

On every major release

Every big change can introduce a new flaw. Reviewing what changes keeps the bar high without redoing everything.

Integrated into your pipeline

Within a DevSecOps approach, the analysis enters your continuous integration and reviews the code on every change, with immediate feedback.

For the CRA or a certification

When the Cyber Resilience Act or a standard asks you for secure development, this is the evidence that you really do it.

Fits with

The code and its execution, complete

The code audit is half the picture of your software security, the inside half. The other half is provided by application pentesting, which attacks the application once it is running: white box and black box together cover everything from the code to its real behaviour. It is also a key piece of the secure development required by the Cyber Resilience Act, and what it finds can feed into the continuous monitoring of Sondriva, our SOC, once your application is already in production.

Questions

Frequently asked questions

What is a source code audit?+

It means reviewing your application code from the inside, looking for security flaws at their source instead of testing the application once it is running. Reading the code reveals things that are invisible from the outside: a hidden credential, poor validation, a code path that almost never runs. This is what is known as a white box audit.

How does it differ from a pentest?+

In the point of view. A pentest attacks the application from the outside, like an attacker, without seeing the code: that is black box. A code audit looks from the inside, with the code in front of it: that is white box. The pentest tells you what can be exploited; the audit tells you why and where the cause lies. They are complementary, and together they cover everything from the code to its execution.

Is it SAST? Do you only use tools?+

We use static analysis (SAST) to sweep through all the code quickly and miss nothing, but we do not stop there. A tool flags many false positives and does not understand your business logic. That is why an expert reviews the findings by hand: discarding the noise, confirming what really matters and finding what no tool sees on its own.

What kind of flaws do you find?+

Secrets and credentials written into the code itself, injection flaws and poor input validation, errors in access control and authentication, misused cryptography, third party dependencies with known vulnerabilities and business logic flaws. And, above all, the root cause of each one, so it gets fixed properly.

Do I need to give you access to my code? Is it safe?+

Yes, we need the code, and that is why we handle it with the utmost confidentiality and under agreement. The reassuring part is that the analysis is static: we read the code, we do not run it, so there is no impact on your production environments or your real data.

Do you also review libraries and dependencies?+

Yes. Today much of any application is third party code, and that is where software composition analysis comes in: we review your dependencies and libraries for versions with known vulnerabilities. This is where a significant part of software supply chain problems slip through.

Can you integrate it into our pipeline?+

Yes, and it is the most cost effective way to do it. Integrating the analysis into your continuous integration pipeline, within a DevSecOps approach, lets you review the code on every important change and give the team feedback as soon as possible. It is cheaper to fix a flaw as soon as it is written than to discover it in production.

What languages and technologies do you cover?+

We work with the most common languages and frameworks in web, API and mobile applications, and we adapt the tools to your specific stack. Tell us what your software is built on and we confirm the scope before we start, with no surprises.

Does it count towards the CRA or ISO 27001?+

It helps with both. The Cyber Resilience Act requires products with digital elements to be developed securely, and ISO 27001 includes secure development controls. A code audit is the evidence that you review the security of your software and that you act on what comes up, not just that you say so.

Direct channel

Shall we talk?

Tell us what your software is built on and what you want to secure, and we will propose how to audit your code and make it safer from the inside.

Get in touch