What Is SAST

Web applications are often most discussed for their features, but source code is still the heart of every web app. SAST tools analyze your source code and flag up common vulnerabilities that can become serious security threats when your web app goes live.

Here’s why your dev team needs to integrate SAST tools into your web application’s development cycle.

SAST stands for Static Application Security Testing. These tests are conducted by automated software programs that analyze sections of your source code for potential vulnerabilities. SAST can be conducted early on in your development cycle even before your application is up and running.

SAST reports feedback in real time allowing your dev team to quickly isolate vulnerabilities and correct them. The information generated by SAST lets you remove flaws in your source code before those vulnerabilities progress further into your development.

The Benefits of SAST

SAST quickly analyzes your source code and provides you with the information you need to correct vulnerabilities before they go live. This is one way to help reduce the risk of human error when double-checking the source code for the features in your application. These tests can be conducted on applications that are not yet completed and are the best way to eliminate vulnerabilities before they become too interwoven in your application source code.

SAST Pros

Identifies weaknesses in source code
Reports are easy to digest for developers
Allows for quick reports and fixes

SAST Cons

Does not report on third-party interactions such as API
Testing becomes outdated when source code changes
False positives are a known risk of SAST

How Does SAST Differ from DAST?

While many individuals might be tempted to compare the pros and cons of SAST vs. DAST, these are two separate tools that are designed to accomplish different jobs. In many ways, this is an apples to oranges comparison.

SAST is designed to look at your source code from within. It gives you quick reporting that developers can easily understand and use to implement fixes. SAST is best conducted early on in your development cycle before your application is ready to go into live testing.

DAST is a much more dynamic test. It’s designed to operate in live environments and approaches your web application from the outside like a hacker would. If SAST is looking for problems in your source code, DAST is looking for ways hackers can exploit your application in the same environment your users will find it.

Why is SAST Important?

There are two realities in every web application development environment that make SAST incredibly important.

The first is that there is simply too much code for humans to manually audit. There can be millions of lines of code in your application which creates a tiring and taxing process for even the most experienced developers to successfully double-check. SAST automates this process and can even be customized to flag up concerns specific to your application.

The second concern is that the realities of development and security are changing. Web application security is now a core part of the development process itself. SAST is a way of integrating your development team into your overall security by presenting security information in ways that developers can easily understand.

SAST can also save you valuable time down the road. By utilizing these automated tests early and often, you can prevent vulnerabilities from becoming deeply woven into your source code. It gets harder to fix vulnerabilities in source code the further down the development cycle you are.

How to Integrate SAST into Your Web App Development

One of the biggest advantages of SAST is that you can run these tests once your application becomes feature-complete. As soon as your source code is fully built out, it’s ready for SAST.

Your development team will be able to understand the reports generated by SAST even with minimal web application security knowledge. This allows you to run SAST early on in your development cycle and fix source code vulnerabilities as they appear.

Here’s a general outline of how to run SAST.

Select a SAST tool that is capable of testing code written in the languages that your application uses
Run your SAST tool while prioritizing high risk applications
Analyze the results of your SAST and prioritize fixes based on your threat modeling
Reintroduce SAST testing as source code undergoes major changes