DAST: A guide to dynamic application security testing

Dynamic application security testing (DAST) as a form of security testing that involves actively testing deployed applications in real-time, simulating real-world attacks to identify vulnerabilities. As the cybersecurity threat landscape has evolved, DAST has emerged as a key tool for enforcing application security in continuous integration and continuous delivery (CI/CD) pipelines.

Incorporating DAST into CI/CD pipelines helps you maintain a robust security posture while achieving the speed and agility necessary to compete in the current software development landscape. It detects potential vulnerabilities and addresses them throughout the entire development lifecycle at a stage when remediation is less time-consuming and costly.

In this article, you’ll learn how DAST can bolster your application security and how you can easily integrate DAST into your CI/CD pipeline for optimal protection.

Understanding dynamic application security testing

Dynamic application security testing actively analyzes web applications for potential vulnerabilities in their production environment. This approach sets DAST apart from other security testing methods.

For example, static application security testing (SAST) analyzes only the unexecuted source, byte, or binary code. It cannot analyze a running application. That means that SAST cannot find vulnerabilities caused during interactions with a running web application, such as input validation issues or authentication weaknesses present in the application’s behavior.

DAST functions by simulating real-world attacks — like those executed by hackers — and observing the application’s response. By closely monitoring the application’s behavior under stress, DAST identifies security vulnerabilities that malicious actors may exploit.

DAST can uncover a wide range of vulnerabilities, including some of the most common ones:

• Structured Query Language (SQL) injection: DAST tools identify the application’s potential SQL injection vulnerabilities by sending crafted input to the application and observing its behavior. SQL injection can lead to unauthorized data access, corruption, or complete system compromise.
• Cross-Site Scripting (XSS): DAST detects XSS vulnerabilities by injecting the application with malicious scripts and observing if the application executes them. XSS attacks can lead to data theft, session hijacking, and application defacement.
• Cross-Site Request Forgery (CSRF): DAST tools identify CSRF vulnerabilities by testing if users can manipulate the application into performing unwanted actions on their behalf. CSRF attacks can lead to unauthorized changes in user data, account takeover, and other malicious activities.
• Broken authentication: DAST helps detect issues with authentication mechanisms, such as weak password policies or improper session management. These vulnerabilities enable attackers to bypass authentication, impersonate users, or gain unauthorized access to sensitive data.
• Insecure Direct Object References (IDOR): DAST can identify IDOR vulnerabilities by manipulating object references (such as URLs or hidden form fields) to access unauthorized resources. IDOR attacks can lead to unauthorized data access or manipulation.

By identifying and addressing these vulnerabilities, organizations can significantly improve their application security and reduce the risk of costly data breaches.

How dynamic application security testing enhances application security

Dynamic application security testing tools typically send requests to the application, looking for vulnerabilities in the application’s response that an attacker could exploit. By doing so, DAST can detect vulnerabilities potentially overlooked by other testing methods, such as static analysis or manual code reviews.

DAST is helpful in production environments as it allows security teams to identify vulnerabilities that new code, configuration changes, or other updates may have introduced.

DAST tools can be easily integrated with CI/CD pipelines to detect vulnerabilities automatically before developers release changes to a production environment. By detecting and addressing vulnerabilities early, organizations reduce the risk of a successful attack and help protect their data and systems. Furthermore, DAST provides a more comprehensive security scanning experience through testing a running application in its deployed environment.

In addition to its extensive scanning capabilities, DAST is vital in helping organizations meet compliance requirements and adhere to industry standards. Many regulatory bodies and industry guidelines — such as the Payment Card Industry Data Security Standard(PCI DSS) and the General Data Protection Regulation (GDPR) — mandate regular security testing to protect sensitive data.

Incorporating DAST into your security processes helps you detect and remediate vulnerabilities more effectively and demonstrate compliance with these regulations and standards. You can use this approach to avoid non-compliance penalties and enhance your brand’s reputation for security excellence.

Adding automated dynamic application security testing to your CI/CD pipeline

When incorporating DAST into your CI/CD pipeline, choosing a suitable DAST tool that aligns with your programming language and framework is essential. Some popular DAST tools include:

• The Open Web Application Security Project (OWASP) Zed Attack Proxy (ZAP): Comprehensive security testing for web applications
• Arachni: A versatile scanner compatible with multiple programming languages
• w3af: A powerful tool focused on identifying web application vulnerabilities

CircleCI simplifies incorporating DAST scans into your CI/CD pipeline by providing pre-built orbs that integrate popular DAST tools such as OWASP ZAP, Arachni, and w3af. These orbs encapsulate complex configurations and enable you to quickly add DAST scans to your pipeline without manually configuring the scanning process or writing extensive code — saving time and effort.

With CircleCI orbs, you can seamlessly integrate DAST scanning into your CI/CD pipeline to thoroughly test your web applications for security vulnerabilities.

To integrate DAST scans using CircleCI orbs:

1. Include the relevant orb in your CircleCI configuration file.
2. Reference the orb within your pipeline by specifying the necessary jobs and commands for your DAST tool.
3. DAST scans are triggered at the appropriate stages of your CI/CD pipeline, enabling you to automate security checks as part of your development workflow.

CircleCI offers a variety of DAST integrations so you can seamlessly incorporate DAST tools into your CI/CD pipeline.

Integrating DAST into your pipeline can profoundly impact the development workflow. It brings security testing to the forefront, enabling developers to identify and address vulnerabilities as early as possible in development.

Using dynamic application security testing in DevSecOps

While DAST is crucial in enhancing application security, it’s only one part of a comprehensive security program. As DAST primarily focuses on testing applications in their running state and simulating real-world attacks, solely relying on DAST for software security may leave certain vulnerabilities undetected.

To build a robust and secure application, a complete DevSecOps pipeline should encompass multiple security testing methodologies.

• Software composition analysis (SCA) testing: Identifies vulnerabilities in a project’s third-party and open source software components
• SAST: Analyzes application code during development to identify potential vulnerabilities before application deployment
• Interactive application security testing (IAST): Combines aspects of both DAST and SAST, monitoring application behavior during runtime and providing real-time feedback on security issues

Read SAST vs DAST to learn more about the nuanced differences between the three methods.

In addition to DAST, SAST, and IAST, a comprehensive DevSecOps pipeline should also include monitoring and observability. These processes offer insights into the performance and security of applications in production. Implementing secure secrets handling is another vital security component that ensures sensitive information — such as API keys and credentials — is securely managed and protected from unauthorized access.

By combining these various security methodologies and tools in your DevSecOps pipeline, you can build and maintain resilient applications and secure them against potential threats.

Conclusion

Dynamic application security testing is essential to modern CI/CD pipelines, allowing for comprehensive security scanning and vulnerability detection in deployed web applications. You can enhance your application security by incorporating DAST into the CI/CD pipeline with tools like CircleCI — while maintaining the agility you need for fast-paced software development .

Try CircleCI for yourself to implement DAST in your CI/CD pipeline. Get started for free.