A Beginners Guide to Dynamic Application Security Testing

dynamic application security testing

Application Security Testing (AST) includes tools for detecting and testing various security vulnerabilities through an automated approach for software development. There are four different types of AST frameworks, mainly static, interactive, dynamic application security testing and software composition analysis (SCA) for analyzing the source code and testing the security of the application.

In this article, we’ll focus on dynamic application security testing (DAST) and the role it plays, similar to a web application vulnerability scanner. DAST adopts the black box testing approach for identifying security vulnerabilities through external attacks on the application on exposed interfaces during its running time.

What is dynamic application security testing?

The ‘dynamic’ aspect of this form of security testing comes from evaluating the security posture of the application during its runtime as compared to static testing which scans the source code line by line at rest. The testing method can be used both during the production phase and the QA environment and is best suited for detecting security vulnerabilities from OWASP Top Ten including SQL and command injection attacks, cross-site scripting attacks, and insecure server configuration.

DAST is mostly used for identifying server configuration and authentication problems along with the security loopholes associated with users logging in. It makes it suitable for noticing problems during the running of the application, an aspect not touched by static security testing. The process of DAST involves automated scanning that takes the form of malicious external attacks to analyze the unexpected outcomes from a set of inputs. For example, particular inputs may go through unprotected SQL databases to check for common injection flaws. It also tests all HTML and HTTP access points through random actions and flawed user behaviour for finding out security issues.

Security experts often specify the provisions and testing parameters of the DAST testing process which implies that they must have a detailed understanding of the application’s working and its usage. There must also be adequate background knowledge about web and application servers, commonly used databases, and application traffic flow for effective implementation of the testing method. DAST finds its use in security testing the web application in its running state as compared to pentesting which utilizes common hacking methods to find vulnerabilities beyond that of applications including firewalls, servers, ports, etc.

Also read types of rootkits.

What are the advantages and disadvantages of dynamic application security testing?

Every testing method has its strengths and weaknesses – here are a few of the DAST testing processes.


➔   Lesser false positives – DAST methodology turns out lesser false positives as compared to other application security testing tools due to the focus provided for each vulnerability without being distracted by other components of the application.

➔   Independent of complicated technology – Since DAST doesn’t look at the source code particularly, it’s not tied to any one language or platform and can therefore be used for different types of applications.

➔   Detects issues in configurations – One of DAST’s strengths since this vulnerability occurs only during operation, the best attack simulation would involve an external attempt to find out other associated configuration issues.

➔   Constant supervision – DAST tools can be utilized for constant scanning and monitoring for vulnerabilities which makes it suitable for today’s environment for immediate discovery and patching up.


➔   Slow scanning procedures – Scanning speed is not one of the positive attributes of DAST, taking as long as five to seven days for completion. The process is also suited for finding vulnerabilities later in the software development lifecycle (SDLC) which requires more time and resources for remediation.

➔   Lack of source code analysis – DAST testing has no code visibility within the application code base which makes it difficult to pinpoint the coding flaws to developers or ensure complete and efficient security posture.

➔   Lack of scalability – The need for fine-tuning tests by security experts makes the testing process too specific to aspects and environments, bringing down the efficiency and scalability.

➔   Absence of data protection – During the scanning process, the DAST tool may cause the data to be overwritten or the insertion of malicious payloads into the target site. Therefore, sites should be scanned in environments that have similar features – but not the exact same – to the production stage for effective results and data protection.

➔   Doesn’t cover 100% of the application – The dynamic testing method cannot cover the entirety of the application within its scope. This implies that the tester should look into the attack surface and the area covered by the web application itself to check if the correct configuration was implemented within the application’s context.

➔   Can’t check for all attack variants – For a given vulnerability, there could be multiple attack methods but DAST testing methods only work with a number of predefined simulations due to its limitations.


These are a few of the aspects that must be kept in mind when the firm decides to engage with dynamic application security testing (DAST), if not already implemented. Along with these features, it’s important that the chosen service provider is able to uphold these points and act in an informed manner when engaging in security testing. (fabulouseyebrowthreading)