What is Dynamic Application Security Testing (DAST)?


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Praise Iwuh

January 26, 2023

What is Dynamic Application Security Testing (DAST)?

What is DAST? 

Dynamic Application Security is a testing technique designed to protect applications from malicious attacks by monitoring them in real time. It uses a variety of techniques, such as data leakage detection, behavioural analysis, and vulnerability scanning, to detect and respond to threats. This type of security also provides protection from zero-day exploits, which are new threats that have not yet been discovered.

Why DAST is Important

Dynamic Application Security is an important tool for organizations looking to protect their applications from the ever-growing threat of cyber attacks. It offers a proactive approach to security, allowing organizations to identify and respond to threats before they can cause any damage. Additionally, this type of security is much more cost-effective than traditional security methods, as it eliminates the need for manual patching and updating.

Today, millions of businesses use web applications to offer services and expand their reach globally. Web applications are programs stored on a remote server and accessed over the internet through a web browser interface. Our favourite apps, Netflix, Gmail, Spotify, Whatsapp, and Uber, are all web applications. They facilitate communication, sales, registration, information banking, and customer service. Unfortunately, the growth of the new age technology backpacks the rise of cybersecurity attacks and breaches.

According to Sitelock's 2022 annual security report, there has been a 210% increase in cyber attacks since 2020. Also, the number of average attacks per site has risen to 172 daily, while the average cost of a general data breach was $4.217 million in 2021. These statistics point out how necessary it is to engage in security testing. The more code we write and the more websites we build, the more there will be an increase in cyber threats and breaches.

These statistics point out how necessary it is to engage in security testing. The more code we write and the more websites we build, the more there will be an increase in cyber threats and breaches.  Shockingly, Cybersecurity Ventures reports that cybercrime has become more lucrative than the notorious international trade of illegal drugs. DAST can find issues in a dynamic environment, which are only visible when the app is run. Its outside-in approach also makes it possible to observe microservice interactions and identify their shortcomings.


Though best practices recommend a blend of two or more different testing techniques, dynamic testing is important because it works by imitating the very threats you seek to defend against, thus finding and fixing loopholes before an attacker arrives to exploit them. 

Dynamic testing:  

  • Protects your applications and code 
  • Identifies vulnerabilities 
  • Provides vulnerability assessment reports to facilitate remediation

Types of DAST 

Although most DAST operations today are automated, it is relevant to note that there remain two approaches to Dynamic testing: 


Manual DAST

Manual testing, as the name implies, involves using human effort, experience and knowledge to uncover vulnerabilities. It is often done by a team of security professionals who test the application for bugs that usually escape automated scanners. It utilises human guile, which computers are still incapable of.

Automated DAST

This technique uses testing software to find and report vulnerabilities automatically. It involves the use of techniques such as crawling and fuzzing. Automated scanning detects a wide variety of vulnerabilities and saves time. You can get a better result by blending both methods, usually in the order of automated first to discover a multitude of errors and manually to identify the few which got past the automated scanning.

How DAST Works

The DAST tool is used when the application enters production or runtime in the initial stages of the software development lifecycle. A DAST tools scan applications from the outside, hunting for vulnerabilities and trying to exploit them. A report is sent to identify the vulnerability whenever it detects a weakness.


In everyday terms, DAST secures a house by testing its defences and trying to break in. It checks the doors and windows for any openings or weak locks through which unauthorised access can be gained. It also attempts to batter down doors and smash windows and then makes a detailed report of how successful its attempts were and why.

DAST works opposite to SAST, where the doors and windows are tested from inside the house. It tests all of your application's endpoints, stimulating different attacks while trying to find vulnerabilities. Dynamic Testing sends an automated alert to the development team concerned for a solution when it finds a vulnerability.  It is important to note that while DAST tools are commonly used for web applications, they also contain features designed to test non-web apps.


To begin implementing DAST, here are a few steps you should follow: 


Interact with Users

It helps to interview your users and document their interactions with your app. This process typically involves recording their activities on the app and their answers to strategic questions about their overall experience with the app. This is to get a clear picture of the 

app’s behaviour in user environments.  


Automate User Interactions  

Next is to script the user’s actions using an automation tool. This works best for Command Line Interface(CLI) and Application Programmer Interface(API) applications, but it is also possible for Graphical User Interface(GUI). 


Integrate Test-Scripts into CI/CD Pipeline  

Once automated interactions have represented your priority use cases, you can then run test scripts against your application while a DAST tool scans it. When the first DAST run is complete, you can start addressing the uncovered vulnerabilities. 


Integrate Regression Tests into Testing Suite  

If you find security vulnerabilities in your application’s day-to-day usage, you can add specific usage scripts to your test suite. This prevents the issues from recurring in the future.


Some of the operations carried out during DAST are: 

Benefits of DAST 

Technology independent

Because DAST doesn’t look at source code, it is not language or platform specific. Not being limited to specific languages or technologies allows you to run one DAST tool on all your applications. 


Low false positives

Based on OWASP’s Benchmark Project, DAST has a lower false-positive rate than other application security testing tools. Testers can zero in on real vulnerabilities while tuning out the noise.


Identifies configuration issues 

DAST excels at finding security vulnerabilities that occur only when the application is operational. In addition, DAST attacks an application from there outside in, placing it in the perfect position to find configuration mistakes missed by other AST tools.


Limitations of DAST 


Not highly scalable  

One of the main downsides to DAST is its heavy reliance on security experts to write effective tests, which makes it very difficult to scale.


No code visibility 

DAST does not have any visibility into an application’s code base. This means DAST cannot point developers to problematic code for remediation or provide comprehensive security coverage on its own. 


Slow scanning 

DAST is not known for its speed, and many users report scans taking too long. Forrester estimates that DAST scans can last 5 to 7 days. In addition, DAST scans typically find vulnerabilities later in the software development life cycle (SDLC), when they are costly and time-consuming to fix.


What is the difference between SAST and DAST?

DAST (Dynamic Application Security Testing) is a type of testing that looks for security vulnerabilities by safely exploiting a running application from the outside. This testing type does not depend on the framework or programming language used.

SAST (Static Application Security Testing) is a type of testing that includes code analyzers. It tests the source code for vulnerabilities by identifying its common patterns. These tools are language-specific and should be used only if you are developing your applications.


DAST and SAST are rightly regarded as opposite application security testing methods. Here we look at their major differences and interactions.


Black-box vs White-box 

DAST is a black-box security testing approach that analyses the app from the outside, while SAST is a white-box method that investigates the software from within. DAST is typically used in tandem with SAST to ensure thorough security evaluation.


Source code examination 

DAST uses operational testing to detect runtime errors, while SAST searches source code when the app is static to assess potential security concerns and construction defects. SAST can detect coding faults down to the code line number, whereas DAST can detect defects in the data flow.


Performance analysis 

DAST determines if a user has the authority to access resources and identifies whether the user is a super user on a rooted device. Static analysis does not allow for this.


DAST works on a live web application, unlike SAST, and can trace vulnerable plugins, which in turn, elevates privilege. During static analysis, little information on memory usage and management is derived. However, dynamic testing detects even the portions of RAM that are susceptible to exploitation.


Can they be used together? 

Yes. SAST and DAST can and should be used together. When DAST tools are used, their outputs can inform and refine SAST rules, improving the early identification of vulnerabilities. This refinement process allows SAST to be the primary method of uncovering issues and DAST to be the verification check before a product is launched.


Differences Between DAST and Penetration Testing(Pentesting) 

DAST is often mistaken for penetration testing. However, they are two different operations entirely. Their major similarity is that they both are black-box testing techniques, which find vulnerabilities from outside and attempt to exploit them. In this section, we will discuss their differences.  


Penetration testing is an application security testing method that detects exploits by simulating a malicious attack. It targets servers, protocol interfaces, or other application systems to determine how susceptible they are to breaches.

Penetration testing involves hiring professional security personnel who will think like a hacker and replicate their malicious actions. These security professionals are experts at breaching applications. They detect breaches and point out the specific weak points for the developers to seal. 


Some key differences between Dynamic application security testing and Penetration testing 


  • DAST works in a dynamic environment and is usually automated, while penetration testing uses dynamic and static methods, and the process is entirely manual. 

  • DAST tools can be run by security teams, developers or automatically without human intervention. On the other hand, Penetration testing requires deep understanding and expertise.

  • DAST tools are mostly automatic, while penetration tests are usually manual (automated penetration testing tools do exist, however). 

  • DAST tools are inexpensive and can typically run as often as needed (depending on the licensing model). Penetration tests conducted by ethical hackers are high-cost and limited to a single, well-scoped penetration test. 

  • Dynamic testing can generate false positives, while Penetration testing does not. However, modern DAST tools increasingly use artificial intelligence(AI) and fuzzing tools to provide reports with minimal to zero false positives.

  • Dynamic testing saves cost because it can discover issues earlier in the development process, while Pentesting is usually conducted on production applications, resulting in a higher cost of remediating issues.

  • DAST tools can be run at any time, enabling continuous testing and scanning of an application. Penetration testing is typically a quarterly or yearly operation.


Top 10 Dynamic Application Security Tools 


Burp Suite 

Burp Suite is one of the world's most popular penetration DAST tools. It is often used for web application security to discover vulnerabilities and remediate them.


Owasp Zap 

ZAP is an open-source tool from OWASP (Open Web Application Security Project). This is a Dynamic Application Security Testing tool you can use to carry out penetration testing and help discover vulnerabilities in your application.



It is an application that currently helps an organisation measure and manage security risk and help remediate security vulnerabilities faster.



Being an external attack surface management tool, Detectify is totally automated and powered by a world-class ethical hacking community. Security teams using Detectify can map out their entire attack surface to uncover anomalies and detect the latest business-critical vulnerabilities in real-time, especially in third-party software, by applying hacker insights.



Invicti is an automated application security testing solution that allows enterprises to safeguard thousands of websites while drastically lowering the chance of an attack.



StackHawk is a contemporary DAST tool designed for CI/CD automation. It helps developers uncover and immediately fix security bugs rapidly. It provides all the necessary documentation and guides in fixing the issue and ways to prevent such issues from reoccurring.


Beagle Security 

Beagle Security is a web application penetration testing tool that aids in the detection of vulnerabilities on your website before hackers exploit them. You can integrate automated penetration testing into our CI/CD pipeline with Beagle Security to uncover security concerns early in the development lifecycle and ship safer web applications.


HCL AppScan 

AppScan is a dynamic application security testing solution for security professionals and pen-testers. Appscan scans the target app and tests for vulnerabilities using a robust scanning engine.



Acunetix is an automated application security testing platform allowing small security teams to take on large-scale security concerns. Acunetix helps enterprises decrease risk across all sorts of online applications with fast scanning, comprehensive results, and intelligent automation.


Micro Focus Fortify On Demand 

Fortify on Demand (FoD) is a Service offering full-featured Application Security. It provides a simple approach to getting started while also allowing for growth. Fortify on Demand also offers in-depth mobile app security testing, open-source analysis, vendor application security management, and static and dynamic security. It removes false positives from every test, and the test results can be evaluated by manual application security.



Dynamic Application Security is an essential tool for organizations looking to protect their applications from the ever-growing threat of cyber attacks. It offers a proactive approach to security and can help protect against zero-day exploits, making it a cost-effective solution for any organization. With the right tools and strategies, organizations can ensure their applications are secure and protected from malicious threats.


DAST will detect threats or security vulnerabilities that are sometimes only visible after an app has been activated, thereby protecting the organisation's product, investment, and reputation. DAST has its benefits and limitations and will be most useful when applied in the right scenarios and alongside other methodologies, such as SAST. 

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