What is Dynamic Application Security Testing? SAST vs DAST?

What is Dynamic Application Security Testing? SAST vs DAST?

Your web application may be vulnerable to new kinds of assaults if you deploy it into a different setting. For instance, faulty application server setups or security control assumptions might not be apparent from the source code. The dynamic application security testing (DAST) technique tests applications for such vulnerabilities in deployed contexts. Dynamic application security testing is also known as “black box” testing, which analyzes an application’s operating state from the outside in and keeps track of how it responds to simulated assaults launched by a testing tool. Applications’ reactions to these simulations may be used to ascertain if they are secure and resistant to actual malicious attacks. In our article below, you can learn more about DAST.

What is Dynamic Application Security Testing (DAST)?

Dynamic Application Security Testing (DAST) is the process of analyzing a web application through the front-end to find vulnerabilities through simulated attacks. By assaulting an application as a hostile user would, this kind of strategy assesses the program from the “outside in.” Following the execution of these assaults, a dynamic application security testing tool scanner searches for outcomes that do not match the expected result set and locates security flaws.

Since the test is run in a dynamic environment, the term DAST includes the word “dynamic”. DAST testing is carried out while the program is active, in contrast to SAST, which analyzes the code of an application line by line when it is idle. This is not to claim that testing occurs when the program is running in a live environment. Testing is often done in a QA environment, even though DAST may be utilized in production. DAST has the advantage of being able to detect runtime issues, which SAST cannot accomplish in its static form. Dynamic application security testing DAST is quite good at identifying issues with server setup, authentication, and weaknesses that are only apparent when a known user comes in.

dynamic application security testing

Why is DAST important?

DAST is important because it enables developers to design apps without having to depend exclusively on their knowledge. Before a program is released to the public, vulnerabilities can be found in it by using DAST during the SDLC. If these flaws are not fixed and the app is used as intended, a data breach might occur, causing significant financial loss and harm to your brand’s reputation. At some point throughout the Software Development Life Cycle (SDLC), human error will unavoidably come into play. The earlier a vulnerability is discovered during the SDLC, the easier and less expensive it is to remedy.

94% of the more than 11,000 Web apps analyzed using Fortify on Demand (FoD) vulnerability data had security feature flaws. During the last four years, concerns with code quality and API misuse had approximately quadrupled (2019 Micro Focus Application Security Risk Report). DAST is a crucial component that can address this issue.

dast dynamic application security testing

How does DAST work?

If a dynamic application security testing scanner discovers holes that allow for attacks like SQL injections, Cross-Site Scripting (XSS), and others, it will automatically deliver notifications to the user. DAST tools can uncover runtime problems that SAST tools can’t since they are designed to work in a dynamic context.

Using a building as an example, a DAST scanner might be compared to a security officer. However, this guard goes a step further by attempting to physically enter the building, as opposed to merely ensuring sure the doors and windows are closed. The guard can attempt to shatter windows or pick the locks on the doors. The guard might report back to the building management after completing this examination and explain how he was allowed to enter the premises. Similarly to this, a DAST scanner actively seeks vulnerabilities in a live system so the DevOps team is aware of where and how to address them.

Pros and Cons

1. Pros

Technology independent

DAST is platform and language agnostic because it doesn’t examine source code. You can run a single dynamic application security test tool across all of your apps since it is not constrained to certain languages or technologies.

Low false positives

In comparison to other application security testing tools, DAST has a lower false positive rate, according to the OWASP Benchmark Project. Testing professionals can filter out the noise and focus on actual weaknesses.

Identifies configuration issues

Finding security flaws that only exist while an application is in use is where DAST shines. Dynamic application security testing also assaults an application from the outside in, which puts it in a prime position to detect configuration errors that other AST tools could have overlooked.

2. Cons

Not highly scalable 

DAST’s substantial reliance on security specialists to create efficient tests makes it exceedingly challenging to scale, and this is one of its key drawbacks.

No code visibility

The code base of an application is not visible to DAST. As a result, DAST dynamic application security testing is unable to independently offer complete security coverage or alert developers to problematic code that needs to be fixed.

Slow scans

Many customers complain that scans take too long because DAST is not recognized for its quickness. DAST scans may take up to seven days, according to Forrester. Furthermore, DAST scans frequently identify vulnerabilities later in the software development life cycle (SDLC), when fixing them may cost more money and effort.

dast pros and cons

What is a DAST tool that is well-suited for developers?

To help you find and solve vulnerable web application vulnerabilities, we offer automated dynamic application security testing.

Since dynamic application security testing simulates attacks on a live program, it is often performed after production. However, by choosing to “Shift DAST left” and shifting DAST earlier in the development process, you can find vulnerabilities sooner and save time and money. We incorporate pre-built scan policies that strike a balance between speed and your organization’s needs.

Additionally, we offer a tool called incremental scanning that enables you to quickly evaluate vulnerabilities in just the parts of the program that have changed.

What is the difference between SAST and DAST?

By targeting an application like a hostile user would, DAST targets the program from the “outside in.” Following the execution of these assaults, a dynamic application security testing scanner searches for outcomes that do not match the expected result set and locates security flaws.

Static Application Security Testing (SAST), on the other hand, examines static environments, i.e., an application’s source code. It performs an “inside-out” analysis of the program, looking for coding flaws.

It’s recommended to employ both SAST and DAST to strengthen your security posture to the fullest extent possible. You can get a full picture of vulnerabilities thanks to this consistent taxonomy across testing techniques.

sast vs dast


Modern DevOps practices require testing solutions that assist protect apps without delaying development for security and developer teams.  DAST is a strong tool in this regard. In actuality, DAST is the second-largest subset of the AST industry after SAST. According to Forrester’s study, DAST is already used by 35% of the firms polled, and many more want to adopt it.

Nevertheless, no one technology can handle all aspects of application security. DAST does a valuable job of identifying possible run-time faults in a dynamic context, but it can never detect a bug in a line of code. Dynamic application security testing doesn’t offer complete coverage by itself.

Because of this, the majority of enterprises require a combination of AST technologies to successfully lower their security risk. DAST excels at analyzing external assault strategies. SAST searches the whole code base for coding faults. They offer the thorough testing approach your company requires, together with a SCA solution to manage your open-source software.

>> Related article: DevOps tools

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