SAST vs DAST
August 13, 2020

SAST vs DAST: What’s the Difference?

SAST
Static Analysis

With security breaches and cyberattacks on the rise, it is essential to use the right tools — like SAST and DAST — to help ensure that your software is secure and safeguarded against vulnerabilities. Fortunately, using the right software security tools and techniques makes the DevSecOps process easier.

Here, we explain the difference between SAST vs DAST to help you better understand when you should use which.

SAST vs DAST: Overview of the Key Differences

Static Application Security Testing (SAST) and Dynamic Application Security Testing (DAST) are both used to identify software security vulnerabilities. However, they work in very different ways.

Here are the most notable differences between SAST vs DAST.

Static Application Security Testing

Here's what you need to know:

White Box Security Testing
Static Application Security Testing is often referred to as white-box security testing (or the “developer approach”), where you have access to the underlying framework, design, and implementation of the software. A Static Application Security Testing tool tests the software from the inside out

Source Code Is Required
A Static Application Security Testing tool doesn’t require you to run your software in order to analyze it for vulnerabilities. Instead, it analyzes your source code, byte code, and binaries, without executing anything, generally providing the fastest possible feedback and requiring the least amount of work.

Vulnerabilities Found Earlier in Development and are Less Expensive to Fix
A Static Application Security Testing tool is able to scan your code as it is being written. This helps to ensure that security vulnerabilities and coding errors are identified as soon as possible. This also makes it easier, faster, and cheaper to fix those issues.

Unable to Identify Timing- and Environment-Related Issues
As a Static Application Security Testing tool scans static code, it is unable to identify timing- and environment-related vulnerabilities.

Generally Supports all Kinds of Software
You can use a Static Application Security Testing tool to analyze most types of software, including embedded software, enterprise applications, mobile applications, web applications, and web services.

Dynamic Application Security Testing

Here's what you need to know:

Black Box Security Testing
Conversely, Dynamic Application Security Testing is often referred to as black-box security testing (or the “hacker approach”), you don’t have access to the underlying framework, design, and implementation of the software and so internal detail is obscured. A Dynamic Application Security Testing tool tests the software from the outside in.

A Running Application Is Required
A Dynamic Application Security Testing tool requires you to run your software in order to analyze it for vulnerabilities.

Vulnerabilities Found Later in Development and are More Expensive to Fix
A Dynamic Application Security Testing tool only analyzes software that can be compiled and run, which means that it can only identify vulnerabilities late in development. This makes it more difficult, time-consuming, and — therefore — more costly to fix errors.

Can Identify Run-Time and Environment-Related Issues
As a Dynamic Application Security Testing tool uses Dynamic Analysis to inspect your software, it is able to identify timing- and environment-related issues.

Related Recorded Webinar: Efficient Security Development and Testing — SAST vs DAST >>

Why SAST vs DAST?

Here are the main advantages of this type of tool:

  • Finds issues by looking for known vulnerability patterns for internationally recognized coding standards for security, as well as safety, and quality.
  • Early defect detection and remediation, which leads to lower costs of remediation.
  • Shift-Left approach — analysis available everywhere, including developer desktop and CI/CD pipelines.
  • Easy to automate, scalable, and automatically provides the highest levels of code coverage.
  • Feedback is fast and provides the exact location of vulnerabilities and their cause.

Why DAST vs SAST?

Here are the main advantages of this type of tool:

  • Analyzes the whole application as it runs, within the full system environment.
  • “Look inside” the application and dynamically analyze execution logic and live data.
  • Language and Source Code independent.
  • Checks memory consumption and resource use.
  • Attempts to break encryption algorithms from outside.
  • Verifies permissions to ensure the isolation of privilege levels.
  • Checks for cross-site scripting, SQL injection, and cookie manipulation.
  • Tests for vulnerabilities in third-party interfaces.
  • Understands arguments and function calls.
  • Record application execution for post-mortem test failure analysis.
  • Catch hard application failures.
  • Unattended script-based dynamic analysis.

SAST vs DAST: Use Both For Your Security Program

As part of an effective security program, both Static Application Security Testing and Dynamic Application Security Testing should be used together, as they are able to identify vulnerabilities that the other may not.

However, one is not inherently better than the other. Both are needed in order to conduct comprehensive application security testing.

For more information on SAST vs DAST, watch our on-demand webinar, Efficient Security Development and Testing Using Dynamic and Static Code Analysis.

▶️ Watch the SAST vs DAST On-Demand Webinar

Alternatively, you can sign up for a Klocwork demo to see how it can help you ensure the security and reliability of your code.

▶️ Watch the Klocwork demo