DAST (Static and dynamic application security testing)

Software application security can be tested using a variety of approaches. Dynamic Application Security Testing (DAST) is one such technique.

But what makes this approach special from the special? Why should you learn this?

That’s what this article aims to answer. Let’s explore DAST, its key differences from SAST, its advantages and disadvantages, and recommended methods for its application.

What is DAST?

Dynamic Application Security Testing (DAST) is a security testing method that is used to test the software application’s security by initiating attacks against the software application during its execution. DAST will identify vulnerabilities when the application while is running. Static Application Security Testing (SAST) will detect the vulnerabilities by scanning the code base. Therefore, DAST can detect potential run-time vulnerabilities.

DAST tools can detect vulnerabilities like cross-site scripting (XSS), SQL injection, and other common security issues. They will use fault injection techniques to detect vulnerabilities. The main goal of DAST tools is to identify vulnerabilities that could be exploited in the real world.

Key Features of DAST

Many features in DAST would make it stand out. The key features are explained below.

Runtime Tests: DAST will identify vulnerabilities during the application’s runtime. As a result, issues that may occur during execution can be identified.
Running Tests Without Source Code: DAST doesn’t require source code access, unlike SAST. Consequently, in situations when source code is unavailable, tests can be run on apps developed by third parties.
Simulating Real-World Attacks: DAST can detect potential ways in which an attacker could exploit weaknesses in a production system by modeling actual attack scenarios.
Pay Attention to External Interfaces: DAST effectively finds vulnerabilities in software applications by testing its web pages, APIs, and other inputs.

DAST vs. SAST

It is crucial to identify the difference between DAST and SAST.

SAST conducts security testing by analyzing the source code or binaries of an application to detect vulnerabilities without executing the application. SAST will identify code smells, insecure coding practices, and configuration errors. DAST will conduct the security testing during the runtime. Therefore, it will focus more on vulnerabilities and issues that can be exploited during runtime.

SAST will find vulnerabilities in the code, like buffer overflows and improper input validation. DAST will find vulnerabilities that occur when the application is operational, like issues with session management and authentication mechanisms.

SAST is typically used early in the development lifecycle, while DAST is used later in the development cycle or during production to identify vulnerabilities that can occur in a production environment.

Now that the difference between DAST and SAST has been clarified, let’s dive deep into the benefits and challenges of using DAST.

Benefits of using DAST

Memory Usage: During the SAST of an application, it is not possible to determine the memory usage. However, DAST can detect different portions of RAM, which can easily be exploited. Since DAST will identify vulnerabilities during runtime, it will also help identify memory consumption. This way, DAST directly helps in testing whether memory usage is exploited.
Encryption: DAST will try to break through the encryption technique used in the software application and assess the impact on business. As a result, companies can tighten encryption mechanisms.
Permission: DAST can detect permission issues and whether the user has the authority to access resources. SAST cannot identify these scenarios since it scans the source code for vulnerabilities. Furthermore, DAST can detect whether any vulnerable plugins will give access as a root user.
Performance: The performance of an application can only be measured during runtime. In SAST, CPU and RAM performance cannot be measured, while DAST will run with different payloads, resulting in identifying the performance of CPU and RAM.

Drawbacks of DAST

Limited Scope: DAST can identify vulnerabilities during runtime. It won’t be able to identify vulnerabilities in the existing code base.
False Positives and Negatives: DAST tools can generate false positives (identifying non-existent vulnerabilities) or false negatives (missing actual vulnerabilities). Automated scanning can generate inaccurate results. As a result, manual testing is required. This additional step may introduce unforeseen costs, delay the securing process, and impact the overall efficiency of the security assessment.
Performance Impact: Running DAST tests on a production environment/live environment will definitely impact the application’s performance since DAST tools will be executed during runtime.
Complex Applications: Testing complex applications with DAST can be difficult. DAST tools might not be able to identify vulnerabilities in complex environments without a proper understanding of the system.

Best Practices for using DAST

Integrate with CI/CD: Integrate DAST in the CI/CD pipeline to enable continuous security testing. As a result, vulnerabilities can be identified in the earlier stages.
Combine with Other Testing Methods: Combine DAST with other testing methods, such as SAST and Interactive Application Security Testing (IAST), to get a complete security check. This will facilitate a more complete view of the application’s security.
Regularly Update Testing Tools: It is very important to update the DAST tools to identify the latest vulnerabilities. Since cybersecurity is a constantly evolving field, it is crucial to stay updated.
Review and Validate Findings: It is crucial to review and validate the results from DAST tests to get accurate results. There can be times when the DAST tools will generate false positives. Therefore, it is important to validate the findings.
Conduct Training: Conduct training sessions to educate teams on using DAST tools and how to identify vulnerabilities using DAST.

Conclusion

Dynamic Application Security Testing (DAST) is an important part of software application testing. DAST will identify vulnerabilities during runtime. There are numerous benefits and challenges to using DAST. Therefore, it is important to consider the best practices when conducting Dynamic Application Security Testing. Compared to SAST, DAST will ensure a comprehensive approach to securing applications.