DAST (Dynamic Application Security Testing)

Master Dynamic Application Security Testing (DAST) for Android & iOS! Explore its strengths, limitations, platform differences, and top tools for building secure mobile apps.

Dynamic Application Security Testing (DAST) is a process for identifying security vulnerabilities in applications during their runtime. DAST is a proactive approach to mobile app security that simulates real-world attacks by injecting malicious inputs into a running app and analyzing its response. Unlike static analysis, which scrutinizes code structure, DAST actively tests the app’s defenses, uncovering vulnerabilities that traditional methods might miss. Think of it as a dynamic sentinel, constantly probing your app’s weaknesses and alerting you to potential security breaches before they can be exploited. DAST is particularly crucial for Android and iOS mobile application developers, as it helps ensure the security of apps frequently targeted by cyber threats. By embracing DAST and these best practices, you can develop safe and trustworthy mobile apps for your users.

Understanding DAST

  • Definition and Working Principle: DAST tools interact with an application from the outside, mimicking an attacker probing for vulnerabilities. They analyze the app as it’s running, without access to the source code, looking for issues such as input/output validation problems, session management issues, and other vulnerabilities that are visible from the outside.
  • Detection Techniques: DAST tools perform automated tests and simulate various attack scenarios. Standard techniques include SQL injection, cross-site scripting (XSS), and input validation attacks.

Critical Benefits of DAST: Fortifying Your Mobile Security Posture

  • Unmask Hidden Vulnerabilities: DAST goes beyond syntax errors, detecting logic flaws, configuration errors, and complex vulnerabilities often invisible to static analysis.
  • Simulate Real-World Attacks: By injecting malicious code like SQL queries or XSS scripts, DAST realistically assesses resilience against genuine attacker techniques.
  • Automate Security Checks: Integrate DAST scans into your development workflow for continuous security monitoring, saving valuable time and resources.
  • Improve App Security Posture: DAST findings inform secure coding practices and vulnerability prioritization, leading to more robust app security.

Common DAST Techniques

  • SQL Injection: DAST injects malicious SQL queries into input fields to test data sanitization. A vulnerable app could suffer database manipulation and sensitive information theft.
  • Cross-Site Scripting (XSS): DAST injects malicious JavaScript into forms or URLs to analyze how the app handles this code. If not escaped, attackers could steal user cookies, hijack sessions, or spread malicious code.
  • Insecure Direct Object References (IDOR): DAST attempts to access unauthorized data by manipulating object references. If successful, attackers could gain access to sensitive user information or files.

DAST in Mobile Application Development

  • Network Communication Analysis: DAST can assess how a mobile app communicates over the network, identifying potential insecure data transmissions. Developers must ensure that data transmitted between the app and the server is encrypted using protocols like TLS.
  • API Security: Mobile apps often interact with various APIs. DAST helps identify misconfigurations or vulnerabilities in these APIs. It’s essential to ensure that APIs have proper authentication and authorization controls.
  • Session Management: DAST checks the security of session management mechanisms. Developers should ensure secure session handling, especially in applications that handle sensitive user data.
  • Data Storage and Handling: Although DAST is less effective in analyzing local data storage than Static Application Security Testing (SAST), it can still detect issues with how data is transmitted and stored.

Integrating DAST in the Development Cycle

  • Continuous Integration and Continuous Deployment (CI/CD): Integrate DAST tools into the CI/CD pipeline for regular security checks. Automate the DAST process to run tests with each build or release.
  • Manual and Automated Testing: Combine automated DAST tools with manual testing for comprehensive coverage. Manual testing is essential for complex security scenarios that automated tools might miss.
  • Feedback and Iteration: Analyze DAST reports to identify and prioritize vulnerabilities. Iteratively improve security measures based on DAST findings.

DAST Best Practices for Mobile Developers

  • Choose the Right DAST Tools: Select tools specifically designed or compatible with mobile applications. Consider tools that offer integrations with other development and security tools.
  • Understand the Limitations: DAST cannot identify source code vulnerabilities or those only visible internally. It should be used with testing methodologies like SAST and manual code review.
  • Regular Updates and Training: Keep the DAST tools updated to ensure they can detect the latest vulnerabilities. Conduct regular training for developers on security best practices and the latest threats.

DAST Limitations: Knowing the Blind Spots

  • False Positives: DAST may flag legitimate user inputs as vulnerabilities, requiring manual validation to avoid unnecessary alarms.
  • Black-Box Nature: Limited visibility into the app’s internal workings can hinder DAST’s ability to detect specific vulnerabilities requiring deeper analysis.
  • Limited Customization: Predefined attack vectors might not cover unique vulnerabilities. Manual penetration testing may be necessary for comprehensive coverage.
  • Integration Challenges: Integrating DAST tools into existing development workflows and CI/CD pipelines can require technical expertise.

DAST in Android vs. iOS: Tailoring Your Approach


  • Open-Source Advantage: Offers flexibility in DAST tool integration and customization for specific security needs.
  • Fragmentation Challenges: Diverse versions and devices can complicate DAST effectiveness. Consider using multiple tools with varying capabilities to address different configurations.


  • Closed Ecosystem: Simplifies DAST tool compatibility but limits customization options.
  • App Store Gatekeeper: Apple’s strict security standards and review process often pre-empt common vulnerabilities, potentially reducing DAST’s immediate impact.
  • Sandboxed Environment: DAST’s ability to analyze internal components is limited. Combine DAST with static analysis and manual penetration testing for a holistic assessment.

Dynamic Application Security Testing vs. Static Application Security Testing

DAST (Dynamic Application Security Testing) and SAST (Static Application Security Testing) are cybersecurity methodologies to identify software vulnerabilities, including mobile applications. Understanding their differences is crucial for mobile application developers focusing on networking and cybersecurity.


  • Nature of Testing: DAST involves testing an application in its running state. This is akin to testing the application in real time while it is being executed.
  • Testing Focus: It primarily focuses on finding vulnerabilities that an attacker could exploit, such as issues with user authentication, injection attacks, and session management.
  • Identification of Vulnerabilities: DAST is good at detecting runtime issues like configuration mistakes, authentication and authorization problems, and other vulnerabilities that are only evident when an application runs.
  • Language-Independent: Since DAST tests the running application, it is generally language and framework-agnostic.
  • Limitation: DAST can only identify vulnerabilities in the exposed parts of the application. It does not analyze source code, so that it might miss issues not apparent in the running application.


  • Nature of Testing: SAST involves analyzing the source code of an application without executing it. It’s like conducting a thorough review of the codebase.
  • Testing Focus: It’s used to identify vulnerabilities in the code, such as coding errors, insecure coding practices, and other potential security flaws.
  • Identification of Vulnerabilities: SAST effectively detects issues at the code level, like SQL injection, cross-site scripting (XSS), buffer overflows, and others.
  • Language-Specific: SAST tools are usually specific to the programming language and framework used in the application.
  • Limitation: SAST cannot identify runtime issues, or configuration errors manifest only when the application runs.

When to Use DAST vs. SAST in Mobile Development


  • Early in Development: It’s best to use SAST in the early stages to catch and fix security issues before they are embedded into the final product.
  • Code-Level Security: When your focus is on identifying and fixing coding errors and security vulnerabilities within the code.


  • Post-Deployment or Late Development Stages: DAST is more suited for applications in the later stages of development or already deployed.
  • Runtime Environment Testing: When you need to test the application in its runtime environment to identify vulnerabilities that emerge during execution.

DAST and SAST Best Practices for Mobile Developers

  • Integrate Both: Ideally, integrating DAST and SAST into the development lifecycle provides comprehensive coverage. SAST can be used in the initial coding phase, while DAST can be applied later or during continuous integration/continuous deployment (CI/CD) processes.
  • Continuous Testing: Regularly schedule both DAST and SAST tests to monitor and improve the application’s security posture continuously.
  • Contextual Analysis: Understand the specific requirements of your mobile application, as some types of vulnerabilities might be more relevant than others depending on the application’s functionality and the data it handles.

Both DAST and SAST have their place in a mobile developer’s toolbox for ensuring application security. The choice between them depends on the development stage, the application’s nature, and the specific security concerns at hand.

In conclusion, DAST is a vital component in the security strategy for Android and iOS app development. It helps developers identify and fix vulnerabilities that could be exploited during runtime, thus enhancing the overall security of mobile applications. Integrating DAST effectively into the development process requires automated tools, manual testing, and continuous learning and improvement.

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