Dynamic application security testing, or DAST, is a process used to evaluate an application’s security while it’s running rather than while it’s in a static state. This method involves simulating attacks on an application, identifying vulnerabilities and analyzing the responses. DAST focuses on the exposed HTTP and HTML interfaces of web-enabled applications, making it an excellent tool for spotting security vulnerabilities that may occur during an application’s active runtime.

DAST is a ‘black-box’ testing method, meaning it tests the application from the outside in—much like a potential attacker might. It doesn’t have access to the source code and instead focuses on the application as a whole rather than its individual components. This external perspective enables DAST to discover potential security threats that static testing methods might miss.

While DAST is an effective security testing tool, it becomes even more potent when paired with a shift left approach.

Understanding the Concept of ‘Shift Left’ in Software Testing

Shift left is a practice in software development where testing is conducted earlier in the life cycle—that is, it’s ‘shifted left’ on the project timeline. Traditionally, testing was seen as the last phase before the release of a software product. However, with the shift left approach, testing becomes an integral part of every stage of the development process from planning to deployment.

This approach has several advantages. It allows for the identification and resolution of issues earlier in the development process, reducing the cost and effort required to fix them later. It also encourages collaboration between developers and testers, fostering a more cohesive, efficient development environment.

Shift left is not just a testing strategy but a philosophy that promotes preventive measures over reactive solutions. It’s about building quality and security into software from the get-go, rather than tacking it on at the end.

DAST in the Context of Shift Left

Importance of DAST in Early Stages of Development

The integration of DAST in the early stages of development is crucial for several reasons. First, by conducting dynamic security testing from the onset, teams can identify vulnerabilities earlier, making them easier and less costly to fix. This proactive approach helps to prevent security issues from becoming ingrained in the code, which can lead to significant problems down the line.

Second, early integration of DAST encourages a security-focused mindset from the beginning of the project, promoting a culture of security within the team. This cultural shift is crucial in today’s cybersecurity climate, where threats are increasingly sophisticated, and the stakes are higher than ever.

How DAST Complements Other Testing Methods

DAST doesn’t replace other testing methods; rather, it complements them. While DAST focuses on external vulnerabilities, other testing methods like static application security testing (SAST) can target internal issues. By combining these methods, teams can achieve a more comprehensive view of their application’s security.

In a shift left approach, this combination of testing methods can be very powerful. By conducting these tests early and often, teams can ensure that both the external and internal aspects of their application are secure. This layered approach to security testing can help to catch any vulnerabilities that might otherwise slip through the cracks.

Incorporating DAST Into the CI/CD Pipeline

1. Understanding the Application Structure

Before we can integrate DAST into the CI/CD pipeline, it’s crucial to understand the structure of the application we’re working with. This involves understanding the layers of the application, the technologies used and the data flows. By analyzing the application’s architecture, you can identify the critical components that need more attention during the security testing phase.

Understanding the application structure is not just about knowing the technology stack. It’s also crucial to understand the business logic and the functionality of the application. This will allow you to create better test cases during the DAST process. Additionally, understanding the application structure will enable you to make better decisions when configuring the DAST tool, leading to more efficient and effective security testing.

Finally, understanding the application structure will help you prioritize the vulnerabilities found during the DAST process. Not all vulnerabilities are created equal; some might be more critical due to the data they expose or the potential damage they could cause to the application. 

2. Configure the DAST Tool

The next step is to configure the DAST tool. This involves setting up the scanning parameters, defining the test cases, and tuning the tool to reduce false positives.

When configuring the DAST tool, it’s important to strike a balance between thoroughness and speed. You want the tool to be able to identify all potential vulnerabilities, but you also want the scanning process to be fast enough not to slow down the development process. This balance can be achieved by carefully selecting the scanning parameters and continuously tuning the tool based on the results of the scans.

Additionally, when configuring the DAST tool, you should consider the unique characteristics of your application. For example, if your application uses a specific technology or framework that is known to have certain vulnerabilities, you should ensure that the DAST tool is configured to test for these vulnerabilities. Similarly, if your application handles sensitive data, you should prioritize testing the components that process and store this data.

3. Integrating DAST Into the CI Pipeline

The next step is to integrate DAST into the CI pipeline. The CI pipeline is a sequence of steps that developers follow to merge their changes into the main codebase. By integrating DAST into this pipeline, we can ensure that every code change is automatically tested for security vulnerabilities.

Integrating DAST into the CI pipeline can be achieved using various tools and plugins. Most DAST tools provide APIs that allow you to automate the testing process. By using these APIs, you can trigger a DAST scan every time a new code change is pushed to the repository. This allows you to catch vulnerabilities early in the development process, reducing the cost and time needed to fix them.

However, integrating DAST into the CI pipeline is not a one-time task. It requires continuous monitoring and tuning to ensure that the testing process remains effective. You will need to update your DAST configurations as the application evolves, add new test cases as new features are developed, and fine-tune the testing process to reduce false positives. 

4. Scan for Vulnerabilities

After integrating the DAST tool, you can start scanning for vulnerabilities. The scanning process involves executing the test cases defined during the configuration phase and identifying potential security issues in the application. Depending on the size and complexity of your application, this process can take from a few minutes to several hours.

During the scanning process, the DAST tool will interact with the application just like a real user would. It will send inputs to the application, observe the responses and analyze them for signs of security vulnerabilities. This dynamic approach allows the tool to identify vulnerabilities that static analysis tools might miss, such as runtime vulnerabilities and issues related to the application’s business logic.

5. Analyze and Prioritize Findings

Once the scanning process is complete, the next step is to analyze and prioritize the findings. The DAST tool will provide a report of the identified vulnerabilities, including their type, location and potential impact. This information should be used to prioritize the vulnerabilities based on their risk to the application and the business.

Analyzing and prioritizing the findings is not an easy task. It requires a deep understanding of the application, the business, and the threat landscape. You need to consider various factors, such as the potential impact of the vulnerability, the likelihood of exploitation, the sensitivity of the affected data, and the complexity of the remediation process. By considering these factors, you can prioritize the vulnerabilities and focus your efforts on those that pose the highest risk.

In addition, analyzing and prioritizing the findings should involve all relevant stakeholders. Developers, security teams, and business leaders should all participate in this process, as they each bring unique perspectives and insights that can help make better prioritization decisions.

6. Remediate and Retest

After analyzing and prioritizing the findings, the next step is to remediate the vulnerabilities and retest the application. Remediation involves modifying the application’s code or configuration to eliminate the identified vulnerabilities. Depending on the complexity of the vulnerabilities, this process can involve simple code changes or significant architectural modifications.

After remediation, it’s crucial to retest the application to ensure that the vulnerabilities have been effectively addressed. This involves running the DAST tool again and verifying that the previously identified vulnerabilities are no longer present. Additionally, retesting allows you to check for new vulnerabilities that might have been introduced during the remediation process.

Remediation and retesting is a continuous process. As new vulnerabilities are discovered and new features are developed, you will need to repeat this process to ensure the ongoing security of your application. This continuous effort is a critical component of the shift left with DAST strategy.

7. Continuous Monitoring and Updates

The final step in incorporating DAST into the CI/CD pipeline is continuous monitoring and updates. This involves regularly checking the effectiveness of the DAST tool, updating its configurations as the application evolves, and tuning it to reduce false positives.

Continuous monitoring and updates are crucial to maintaining the effectiveness of your shift left with DAST strategy. As the application evolves and the threat landscape changes, the DAST tool needs to be updated to remain effective.

Conclusion

In conclusion, incorporating DAST into the CI/CD pipeline is a powerful strategy to enhance the security of your software. By understanding the application structure, integrating DAST into the CI pipeline, configuring the DAST tool, scanning for vulnerabilities, analyzing and prioritizing findings, remediating and re-testing, and continuously monitoring and updating, you can unleash the power of shift left with DAST. This comprehensive approach will allow you to identify and address security vulnerabilities early in the development process, leading to more secure and reliable software.