Do Son 
Over the last two decades, a slew of new software development methodologies emerged, completely overhauling software testing. These methods completely changed the way people approached testing. Due to the complexities of modern applications, testing was now considered essential at every stage of the SDLC. Quality assurance and control have become more important at every stage.
Many effective testing automation tools, such as oxeye.io, have arisen due to the requirement of ensuring that consumers are receiving the value promised by software. These technologies make it easy to do application security testing in an automated and repeatable manner. Many tools either utilize a Static Application Security Testing (SAST) or a Dynamic Application Security Testing (DAST) approach. There are also tools emerging that perform a type of grey-box testing which is a combination of both.
SAST Explained
SAST is a form of white-box testing, which means it needs access to the source code to work. SAST testing is done early in the Software Development Life Cycle (SDLC), making it easier to spot any inherent security flaws.
Because SAST examines code before it is compiled and warns of flaws, it can be implemented early in the software development cycle. Fixing the code after the application had been compiled could result in many unnecessary man-hours fruitlessly spent. High-risk concerns can be rectified without breaking the application development by detecting security code early rather than testing immediately before release or in post-production. Security testing can be carried out at any point during the software development lifecycle, decreasing the danger of vulnerabilities making their way into the final product and the risk of hackers gaining access to it.
Source Code Analysis utilized by SAST techniques can detect high-risk software vulnerabilities such as SQL injection, buffer overflows, and cross-site scripting. These types of vulnerabilities can plague a system for the rest of its production existence, opening the door for request forgery or even total system failure.
SAST software is relatively quick without sacrificing quality. Conducting source code reviews can be done in a variety of ways. The auditor uses a top-down technique to look for specific sorts of vulnerabilities in the source code without having a deep understanding of how the program works. In some circumstances, this method may be effective, but any vulnerability that requires knowledge of the program’s inner design will be missed. The bottom-up technique considers a thorough understanding of how the software operates. This method is thorough, but it takes a long time and costs a lot of money.
SAST tools can simply be integrated into an organization’s existing software development lifecycle process. They’ll work with bug trackers, source repositories, and other testing tools in an integrated development environment. Security testing will be more consistent and thorough because of the easy interaction.
There are some scenarios where SAST is not ideal though.
To test application code, it becomes necessary to synthesize data, which could lead to false positives at times. SAST’s language dependence makes it harder to create and maintain tools because it necessitates separate tools for each language utilized. Argument calls also introduce practical limitations, especially when the application is heavily dependent on them.
DAST in Comparison
DAST, also called black-box testing, on the other hand, runs security tests from the outside of a live application rather than looking at the source code or the design within. To perform evaluations, DAST requires the application to be running. The use of dynamic application security testing can expose many security issues in the operational deployment of a software application. DAST can identify several security vulnerabilities associated with a software application’s operational deployment. DAST enables testers to imitate a malicious actor’s actions, assisting in the detection of numerous security problems that would otherwise go undiscovered by traditional testing approaches.
From this technical comparison, it should be clear that various circumstances will warrant one style of automated testing over the other. In scenarios where environments are highly automated careful thought should be put into which style would suit the end goal best. Ultimately a synergy between the two methodologies would be far more effective than either alone. This is often called grey-box testing. It allows applications to be tested in their various states of operability.