What is Static Application Security Testing - SAST?

What is Static Application Security Testing (SAST)?

Static Application Security Testing (or SAST) is a technique to analyze your source code and find security flaws in your application. SAST tools analyze your source code and find potential vulnerabilities that are fixed before deploying your code into production. SAST tools do not need the compiled code and can be used before the code is ready to run.

As SAST tools need the source code, it is commonly referred as “white box testing”.

When to start using Static Application Security Testing (SAST)?

You can start using SAST tools early in your development process. You do not need to wait to complete your application before using a SAST solution.

SAST tools can report issues at multiple stages in the Software Development Lifecycle:

1. When developing and maintaining code: when a SAST tool provides IDE plugins, developers have real-time feedback in their editor, and potential vulnerabilities are highlighted. Developers can then take action and fix the issues before committing code.
2. In the code reviews: automated code review tools highlight potential issues in the code and report security issues in the pull request. Developers are then notified of the issue, and they fix it before merging the code into the default branch.
3. Once the code is published: developers, engineering managers, or CTO use code analysis platforms that report all security issues and vulnerabilities in a dashboard.

As for all processes, the best is to start using the tool and discover security issues as early as possible. The best approach is to use SAST tools across the Software Development lifecycle so that issues are fixed when the code is written. Developers, Managers, and CTO can then periodically monitor the quality of their code in a code analysis platform and verify that no issue has been introduced.

The Importance of Static Application Security Testing (SAST)

In a world where cyber-attacks are common, cyber security is of primary importance, a SAST tool is highly recommended. It not only guarantees that security issues are fixed but also constantly monitors the codebase for outstanding security issues.

Specifically, SAST tools will find any vulnerabilities in your software, including insecure coding patterns, outdated and insecure third-party libraries, and credentials in code.

Static Application Security Testing (SAST) Techniques

SAST tools analyze applications by transforming them into an analyzable representation (known as Abstract Syntax Tree or AST). A database of rules then analyzes this AST. Each rule detects one or multiple security vulnerabilities. Rules detect issues such as Common Vulnerability and Exposures (CVE) or Common Weakness Enumeration (CWE).

The tool reports all issues found, either in the developer code editor, in a code review, or a consolidated dashboard. If you want to understand all the details on how static analysis works, you can read our blog article dedicated to this topic.

What is Dynamic Application Security Testing (DAST)?

Dynamic Application Security Testing (or DAST) analyzes a running application. It requires the application to be completed and running but does not require the application source code. As DAST need a running application, they are typically used at the end of the Software Development Lifecycle.

As DAST does not require the source code of the application, it is commonly referred to as "black box testing”.

SAST vs. DAST

SAST can be used early in the software development process. With SAST, engineers find vulnerabilities before shipping code, ensuring that the code does not contain any vulnerabilities. DAST will find other potential issues, such as configuration and deployment issues that can also introduce vulnerabilities.

Static Application Security Testing (SAST) Tools

There are multiple tools available on the market. Most tools are standalone applications that must be integrated into your software development process. A comprehensive list of existing SAST tools is available on the OWASP website.

Integrating such tools in your infrastructure is time consuming and error prone. It often requires a dedicated team focused on deploying these tools and ensuring they are up to date. For this reason, it's often better to rely on integrated, cloud-based platforms.

If you are looking for a fully integrated platform that checks code at all the stages of the software lifecycle, Codiga is a SAST tool that supports 12+ languages. Codiga reports security issues everywhere in the developer environment: in the IDE, code reviews, and a consolidated dashboard. Codiga not only detects CVE and CWE in source code, it also finds potential leaked passwords and API keys in source code.