Why DAST Testing is Important

Testing applications for security flaws during production is a vital process of the development lifecycle, and this is where Dynamic Application Security Testing (DAST) comes in. DAST is a security testing approach in application security (AppSec), in which testers assess an application in real-time, while it’s actively running. This process can be conducted even without testers knowing the application’s internal interactions or system-level designs.

Applications fuel the engine of the world’s economy, but enterprises can encounter substantial hurdles when striving to retain a competitive advantage in a rapidly changing digital landscape. Businesses must continuously pursue inventive solutions, even as they contend with sophisticated adversaries looking to exploit opportunities to disrupt operations, compromise vital information, and inflict harm.

According to recent research, approximately 17% of cyberattacks aim to exploit vulnerable web applications. Yet, 98% of web applications are susceptible to attacks that can lead to malware infection or redirect users to malicious websites. All the while, 72% of these vulnerabilities result from coding errors.

Testing applications for security flaws during production is a vital process of the development lifecycle, and this is where Dynamic Application Security Testing (DAST) comes in. DAST is a security testing approach in application security (AppSec), in which testers assess an application in real-time, while it’s actively running. This process can be conducted even without testers knowing the application’s internal interactions or system-level designs.



This is because DAST tools operate without access to the application’s source code. Instead, they emulate genuine attacks, akin to those carried out by real hackers, to identify security weaknesses. This “black box” testing method examines the application from an external perspective, scrutinises its runtime behaviour, and observes how it reacts to simulated attacks. These simulations help evaluate whether the application exhibits vulnerabilities and if it is potentially susceptible to malicious attacks.

A recent survey involving 378 application developers and security professionals revealed that many organisations deploy code that contains known vulnerabilities in their production environments. Approximately 45% of the respondents cited the need to meet critical project deadlines, the perception that the vulnerabilities are low-risk, or discovering the security flaws late in the release cycle. However, it’s essential to recognize that releasing code with vulnerabilities poses a considerable risk.



These findings underscore the critical importance of integrating security testing solutions like DAST early in development. Failing to test, assess, and address risks accurately can lead to severe repercussions when deploying code with well-known vulnerabilities. In fact, 60% of survey participants admitted that hackers target their production applications to exploit vulnerabilities listed in the OWASP Top 10. The OWASP Top 10 catalogues the most pressing security risks in web applications, including but not limited to injection attacks, inadequate authentication, sensitive data exposure, insufficient access controls, and security misconfigurations, among others. These kinds of issues should not persist in production code, and integrating DAST early in the development lifecycle can help mitigate them.

DAST techniques first detect potential input fields in the application being tested. Then, it subjects the input fields to various malicious inputs, including attempted exploits of well-known vulnerabilities, such as SQL injection and XSS vulnerabilities, or unusual inputs that may reveal security problems related to input validation and memory management.

The aim of sending the varied inputs is to enable the DAST technique to evaluate how the application responds to detect the presence of specific vulnerabilities related to unexpected or anomalous input that may not have been considered by developers. For instance, if an SQL injection attack results in unauthorised data access or the application crashes due to invalid input, these outcomes signal the presence of exploitable security weaknesses.



Furthermore, DAST tools conduct automated scans that replicate adversarial external attacks on the target application to identify unexpected and potentially detrimental outcomes. As an illustration, a DAST test can introduce malevolent data to detect injection weaknesses. Typically, DAST tools assess all HTTP access points to unearth vulnerabilities by simulating random user actions or behaviours.

1. Comprehensive Automated Security Testing: DAST provides exhaustive security testing options, including ad-hoc, continuous, and scheduled continuous assessments, which underpin agile AppSec practices. This adaptability aligns seamlessly with the dynamic nature of modern applications, offering swift responses to evolving threats. Moreover, with diverse testing modes, DAST enables proactive vulnerability resolution and routine security evaluations, helping organisations stay agile in the ever-shifting threat landscape.
2. Complete Vulnerability Coverage: Today’s applications confront a broad spectrum of threats, from well-known vulnerabilities to emerging zero-day risks. Fortunately, DAST’s ability to cover the entire OWASP list of the most critical vulnerabilities, and its extensive repository of known flaws cements it as an essential component of modern application security testing practices. The current security landscape is characterised by security threats that continually mutate, making DAST stand out as a robust defence against potential risks.
3. Seamless Integration with Build Servers: The seamless integration of security testing into the development pipeline is pivotal in modern software development. Thus, DAST’s compatibility with popular build servers, such as MS Azure DevOps, Team City, and Jenkins, streamlines the security evaluation process. In a world where rapid code deployment is the norm, this integration empowers organisations to safeguard their applications throughout the software development lifecycle (SDLC), diminishing the risk of deploying vulnerable code into production.
4. Streamlined Vulnerability Management: Effective vulnerability management ensures that released software products are secure. In this regard, DAST’s integration with in-house ticketing systems like JIRA simplifies the workflow, enabling development teams to monitor, prioritise, and resolve security issues efficiently. This streamlined approach is essential in the fast-paced application development environment, guaranteeing prompt and effective vulnerability resolution.
5. Automation for Complex Web Applications: Modern applications are becoming increasingly complex, with single-page applications (SPAs) becoming the norm. DAST’s prowess in navigating these complex structures is a valuable asset in today’s landscape. Furthermore, DAST ensures that even the most convoluted applications undergo thorough security testing, addressing vulnerabilities that may elude conventional assessment methods.
6. Comprehensive API Security Testing: In an era where APIs play a central role in application functionality, DAST’s capability to meticulously scan and test APIs, including WSDL, Swagger, and GraphQL endpoints, ensures the security of both front-end and back-end components. This completeness aligns with the modern application’s reliance on APIs, leaving no part of the attack surface unexamined.
7. Vulnerability Monitoring: Vulnerability tracking is fundamental in modern application security. DAST’s ability to identify trends and pinpoint the most vulnerable areas in the production environment enables proactive risk mitigation. Such real-time insight is indispensable in a landscape where threats rapidly evolve since it enables organisations to promptly address emerging risks and reduce the window of vulnerability.

For some time now, applications have been the preferred attack vector for attackers looking to compromise sensitive information or gain a foothold in an organisation’s network systems. A State of Application Security report found that applications are the prime focus, with web application exploits ranking as attackers’ third most frequently employed technique.

Given this reality, organisations must subject their live web applications to the same scrutiny as malicious hackers do. The objective here is to uncover and address vulnerabilities proactively to prevent external actors from discovering and exploiting them.



Although many development teams routinely perform static application security testing (SAST) and software composition analysis (SCA) on their code before deploying, utilising DAST tools within the application’s runtime environment is equally vital. It is worth recognising that prevalent vulnerabilities cannot be adequately assessed within the source code since some only emerge once you deploy code in a production environment. As such, this underscores DAST’s pivotal role in a comprehensive application security testing strategy.

While compliance requirements, legal regulations and industry standards mandate encryption, DAST takes a unique approach by assessing the effectiveness of encryption techniques. Specifically, DAST tools attempt to breach the implemented encryption mechanisms. Such a simulation tests the resilience of encryption methods, focusing on potential impacts on business operations. For example, in APIs, DAST emulates attacker tactics to probe encryption mechanisms, examining their vulnerabilities. It is a comprehensive approach to encryption assessment that ensures that potential weaknesses are uncovered and can be addressed proactively.

Dynamic testing also goes beyond conventional access control checks. It verifies if users can access authorised resources and if they can gain unauthorised entry through injecting malicious scripts. As a result, DAST uncovers scenarios where plugin vulnerabilities grant elevated privileges. In contrast, other solutions like SAST concentrate solely on scanning the source code, missing these real-time application security concerns. The real-time nature of DAST’s approach is crucial in identifying and mitigating security risks that might go undetected.

Lastly, back-end security is a critical area that developers must put more emphasis on. DAST examines scenarios where attackers could compromise authentication and authorisation tokens to exploit the trust relationship between the back end and the application. Fundamentally, it comprises testing for vulnerabilities such as cross-site scripting and SQL injection, enabling a comprehensive assessment of the application’s security posture. The assessment includes the potential compromise of user access session cookies. This comprehensive assessment helps organisations strengthen their back-end security, reducing the risk of critical security breaches.

• Early Integration: DAST can seamlessly integrate into the software development lifecycle (SDLC) during the building phase. As a result, this enables security testers to observe the application’s behaviour in the HTTP environment, allowing them to simulate attacker actions without the need for the extensive, costly penetration testing process.
• Complex Environment: DAST excels in uncovering risks that result from the complex interactions of modern APIs, microservices, frameworks, and various components. Even when these components are individually secure, they can introduce unforeseen challenges when working in concert within a web environment.
• Real Risks: DAST pinpoints issues that genuinely pose risks instead of merely highlighting vulnerabilities that may or may not translate into actual threats. On the other hand, using SAST as the primary testing solution may cause difficulty in discerning whether a finding corresponds to a tangible risk, which can be a perplexing task.
• CI/CD Integration: DAST smoothly integrates into the Continuous Integration/Continuous Deployment (CI/CD) process, commencing as early as the building phase. In agile development scenarios, where applications can become operational within hours of a software development cycle, DAST paves the way for early detection of critical security threats, allowing developers to address high-risk vulnerabilities promptly.
• Context and Proof: DAST identifies vulnerabilities, demonstrates the attack, and offers evidence of exploit for each risk discovered. As such, this provides developers with valuable context, affirming the existence of vulnerabilities and streamlining patch testing and implementation without necessitating additional scans.
• Reduced False Positives: Compared to SAST, DAST exhibits a lower rate for false positives. Most developers consider this paramount since resolving security issues can be time-consuming, and false positives can lead to unwarranted delays. Initiating the security assessment process with DAST helps avert unnecessary holdups by concentrating on vulnerabilities with substantial real-world risks.

DAST stands as a robust choice for fortifying security. Its capacity to evaluate genuine risks, compatibility with complex environments, and seamless integration into the development workflow provide a pragmatic approach to identifying and mitigating security vulnerabilities as part of your security endeavours.

Most organisations aspire to dismantle the barriers that frequently separate development and security teams. While not a universal remedy, DAST plays a vital role in mitigating friction, seamlessly integrating security into the developer’s workflow, and elevating the overall security stance of your organisation.

Shifting security to the early stages of the Software Development Cycle ensures that genuine security issues surface more rapidly. In this case, automation becomes a pivotal ally in reducing the necessity for manual testing, leading to accelerated time-to-market and alleviating the bottleneck resulting from the disproportionate ratio of one security analyst for every one hundred developers. For this reason, DAST allows developers to initiate scans and independently address issues while granting the security team oversight to confirm the successful execution of testing and remediation—without the constant requirement for hands-on involvement. Through DAST, security teams gain a more comprehensive view and increased control over what, when, and how to conduct testing.

On the other hand, DAST provides developers with lucid and actionable results. Interactive reports provide them with prioritised lists of the most critical risks, simplifying access to and analysis of essential data. Furthermore, a proficient DAST solution equips them with the capacity to understand the context thoroughly, examine details from various angles, and efficiently streamline their mitigation actions. When a DAST tool permits real-time attack replay, developers can independently verify the existence of vulnerabilities, assess associated risks, and validate fixes.

While it might be impractical to anticipate perfect alignment between security and development teams, given their distinct cultures, timelines, and incentives, DAST can make substantial headway in bridging the gap and fostering a collective sense of security ownership. With DAST in place, security can keep pace, and development can consistently deliver applications with enhanced security.

Now that you understand the importance of DAST and how it can benefit your organisation’s application security and DevSecOps practices, how do you perform actual DAST testing?

1. Identify the applications to be tested: You must compile a comprehensive list of web applications or websites that you intend to assess for security vulnerabilities. This can include internally developed software, third-party applications, and online services. Understanding the target is crucial for effective DAST.
2. Determine the vulnerabilities the test should target: Selecting vulnerabilities should be based on a thorough understanding of the application’s architecture and potential security threats. The aim is to tailor the DAST scan to focus on the specific threats most relevant to your application.
3. Select an appropriate DAST tool(s): DAST tools are specialised software designed to simulate real-world attacks on web applications. They utilize various scanning techniques, including black-box testing, to identify security vulnerabilities. Choosing the right tool is crucial to practical testing.
4. Run the test and evaluate the results: Once you determine the applications, vulnerabilities, and tools, configure the DAST tool to run against the target web applications. The tool sends a series of HTTP requests and analyses the responses, searching for signs of vulnerabilities. Analyse the results to identify and categorize potential security issues.
5. Mitigate the identified vulnerabilities: Vulnerability mitigation typically involves developers and security teams collaborating. Developers must patch or mitigate the vulnerabilities while the security team monitors the progress and re-tests to ensure that the vulnerabilities have been effectively resolved.