This is a question that every firm wishing to engage in precautionary security looks to answer in order to ensure the security of the application’s internal features. Similar to the black box penetration testing approach, the dynamic application security testing (DAST) method is best dealt with by providing the least background information.
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The DAST methodology comes in the form of automated and manual techniques so that the latter can be used to provide an edge to the former. In this manner, there are various features that must be ironed out before proceeding with the testing process for achieving the best results.
The automated approach of dynamic application security testing
The DAST methodology is broad enough to cover both automated and manual testing techniques by exposing the security tester to limited information about the internal aspects. This ensures that the attack is as similar to a real-time hacking attempt as possible.
Under automated pen testing, the tester analyzes the environment to get a better perspective about its target and potential weaknesses for exploitation. Automated vulnerability scanners can be used to ‘crawl’ the web application, where the crawler refers to a type of bot programmed to visit websites. It logs each webpage to capture useful information and uses it for crafting a map that can provide guidance during the attack later. The development of crawlers according to the context of each web application while incorporating its dynamic nature, purpose, and business logic, is a complicated task and may require manual interventions.
After this, the automated software would peruse the web application for potential security vulnerabilities using different techniques such as brute force and DDoS attacks, password crackers, code injection attacks, and ‘fuzzing’ to break into the system. Good scanners will be tuned for detecting a great number of vulnerabilities, some of which may not be detected by the specialized attack methods used during the pentesting phase. The best approach to ensuring overall web application security testing often comes from the combination of static, out-of-band, integrated, and dynamic application security testing techniques.
If the firm has many web applications for security verification or the developers use a DevSecOps approach for app development, it’s often better to continuously deploy automated DAST solutions to ensure overall enterprise security.
The manual approach of the dynamic application security testing
Every business is different and no hacker will keep resorting to tried-and-tested techniques every time – this is where manual testing and human creativity plays an important role. An ideal testing procedure is the combination of automated and manual testing procedures where the former is used to capture all of the easily discoverable security issues. The latter is then used to provide a more interesting perspective on the security posture of the web application with the help of other exploitative techniques. Some testing teams utilize an intercepting proxy that monitors all of the incoming and outgoing website traffic between the client’s browser and the application. If there is a lack of encryption and the hackers are able to intercept and read all of this information, it’s a clear vulnerability that can be exploited by real hackers and must be resolved immediately.
Testers can also use this opportunity to change the responses sent to the server through the browser, which allows the evaluation of various potential vulnerabilities.
The general outlook on dynamic application security testing
There are both advantages and disadvantages associated with the DAST approach:
- More practical – the main advantage of DAST is the more realistic results and security measures obtained as compared to static application security testing (SAST). Just looking at the application’s source code for bugs can turn out false positives, which is a much lesser occurrence in DAST. Verifying false positives through exploitative techniques can use up a significant amount of time and resources, giving an edge to DAST over SAST.
- Highly adaptable – DAST techniques are language-agnostic which means it doesn’t require multiple frameworks and implementations for the source code of different web applications. This is especially useful if the firm has a number of web applications under its purview with a wide range of programming languages and frameworks.
- Not to be used solo – in blind testing approaches, DAST methods turn out a lot of asynchronous bugs where the application is vulnerable to a bug but the testing doesn’t note this issue. When used with other application security testing (AST) methods, this problem gets resolved.
- Not sensitive to certain aspects – DAST methodologies often tend to miss hidden inputs and hard-to-execute pathways since its perspective is mostly focused on the external side of the web application. This means it can easily miss attacks that use multiple input variables for breaching the application and often requires separate manual review to understand its impact.
These are some of the insights associated with dynamic application security testing that firms must be aware of before engaging the services of a third-party service provider.