This comprehensive tutorial explains what is Dynamic Application Security Testing (DAST), its types, working, implementation, examples, etc:
DAST is also called a web application scanner that is used for black-box security testing. It does not have access to the source code rather it penetrates an application from the outside of the code by merely checking all the interfaces that could be exposed to vulnerabilities.
SAST scans application source code line by line and it’s always done on an application that is at rest, not a running application while DAST testing is done in a dynamic environment and executed while the application is running.
The execution of the application does not mean that the application must be in production before DAST can work. You can integrate DAST tool into your testing environment and use it for testing before deployment to production and the same DAST tool can also be used in the production environment.
Some of these vulnerabilities according to OWASP top 10 that DAST detects are cross-site scripting, SQL injection, command injection, server misconfiguration, session management, secure request, and many more.
What You Will Learn:
What Is DAST
One major advantage of the DAST tool is that it can identify any runtime problems which the SAST cannot accomplish. Some of the problems that generate via server configuration and authentication through the login or other forms can quickly be arrested by DAST.
Working On Dynamic Application Security Testing
DAST performs penetration testing by simulating attacks on an application to identify any vulnerabilities within.
For example, you can try to inject some malicious inputs via DAST and see how the applications will respond. Dynamic Application Security Testing will always test all HTTP and HTTPS requests going into the application and check where the request can be intercepted and used to have access to the application.
It does not work like SAST even though both are used to detect vulnerabilities. While SAST points the developer to where to fix in the code, DAST does not point to any specific lines in the code for remediation.
DAST tools are mostly used by security experts who understand the operation of the full application. They must know how the application works. They also need to have knowledge of other resources that are used for building the whole application like the database, application server, and web server.
How To Implement DAST
Implementing DAST to your CI/CD pipeline is not that simple when compared to SAST. It can be automated and can also be operated manually. Since DAST relies on the execution of your application, adding it to your testing pipeline isn’t as simple as adding SAST to your development environment.
Even though Dynamic Application Security Testing uses an automated process for security testing but the part that needs automation can be carried out through scripting or recording.
Follow the below processes for implementing DAST:
#1) Interaction with end-users
One good way to start the implementation of this tool is through interaction with end-users on their use of the application. You can record all the actions they perform on the application and ask them some vital questions about their experience with the application.
During this interaction, the security expert may see some areas on the application that may be exposed to security attacks. While clicking some functional areas on the application may expose some vulnerabilities in the application that warrants a proper scan with the DAST tool that will explain the issue further and what can be done to remediate it.
#2) Automate end user’s Interaction
We can as well use an automation tool to form a script for all the user’s actions on the application. This process also helps in achieving success in the implementation.
#3) Test Scripts and CI/CD Pipeline
While doing the automated interactions, the test script created can be run during the DAST scanning process. After this scanning, all the vulnerabilities found can be immediately remediated.
#4) Scan with Reporting
After every scan, make sure there is an appropriate report that is generated on time and immediate feedback is given to the developers so they could start the vulnerability remediation.
Benefits Of DAST In DevOps
These are as follows:
#1) Using early: When you integrate DAST into your DevOps very early, you reap the reward of detecting vulnerabilities very early and remediating them quickly. It is very important to integrate it into your testing environment so that the tool can discover any weakness very early and will reduce the cost of remediating security issues at production.
Detecting vulnerabilities at production could be disastrous as this could result in a financial lawsuit from people using the application and could damage the company’s image.
#2) Ability to collaborate with other tools: Not only will DAST provide you with the right information concerning the prompt remediation of the issue it will also help you prioritize all the vulnerabilities detected. It will also help to give feedback to the team that will handle the remediation.
It can be easily integrated with a bug tracking tool that helps monitor how bugs in an application are fixed. When a security bug has priority attached to it, the team assigned to fix the issue will know how to react fast to the remediation.
#3) Every Pentester’s tool: One of the best tools for every application security tester is a DAST tool. This is a fantastic tool that can easily and quickly help to scan an application for any hidden security weakness and help to protect an application from an intruder whose primary aim is to cause havoc.
Although, many security testers have adopted the approach of using a SAST and DAST together.
Comparison With Other Security Tools
While SAST focuses on the source code and it’s used very early in the CI/CD pipeline to identify any coding standard that is not acceptable and goes against the best practices and is dependent on a programming language.
DAST, on the other hand, is generally applied towards the end of the CI/CD pipeline it is black-box testing that does not access the source code and prevents regression. It’s a security tool that is not programming language-dependent.
IAST is similar to Dynamic Application Security Testing because it also focuses on the application behavior during runtime. While IAST security analysis is more of black-box testing, application scanning, and analyzing the behavior and flow of the application. It also bridges all the findings in DAST with SAST findings but its limitation is that its programming language-specific.
Both IAST and DAST can be used later in the CI/CD pipeline.
While SCA (Static Composition Analysis) focuses more on third-party code dependencies in an application, software composition analysis is mostly used for applications that are developed with many open source libraries and it’s also language-dependent.
DAST tool does end-to-end testing without knowing if the code follows normal input sanitization best practices. Unlike the SAST tool, Dynamic Application Security Testing does not know where in the code the sanitization has been implemented.
SAST and SCA tools will always come in handy where some security defects escape the notice of the Dynamic Application Security Testing tool. SAST and SCA will always check the source code and expose the area in the code that has security issues which many times the DAST tool will not discover.
Pros And Cons
Just as DAST tool has its benefit while scanning a runtime application it also has some other disadvantages. We will now list the pros and cons of using a DAST tool and you can then decide if it is the best option for your development environment.
- Low False Positives: Based on different security tool assessments carried out it was found that DAST tool rarely scans the complete application that includes the code which results in it giving lower false positives and lower noise when compared to SAST. This reduced figure will always help in the remediation faster and confirm if the alert is genuine or not.
- Non-Language Specific: This tool is not programming language-specific or technology-dependent. It does not need to have access to the source code before it can discover security vulnerabilities. If you have different programming language projects, then DAST is a very valuable option for your security testing because it can run on any language or platform.
- Quick Vulnerability Fix: It is one fantastic tool that helps in security regression testing. When a security vulnerability is found, this can be recorded and can help in reproducing what lead to the issue and help in quick remediation of the issue and point to a guide on what to do to avoid a re-occurrence of such an issue.
- Identification of Configuration Issues: It is a very good security tool that can detect any configuration issue in an application. When such is noticed, it can be quickly corrected and fixed.
- Runtime Security Tool: This tool performs optimally on an operational application or a runtime application in the testing environment. It is used to simulate attacks from outside the application and can discover security issues that were not detected by other AST (Application Security Tools).
- Source Code inaccessibility: While DAST only checks the inputs and outputs and the application reaction to simulated attacks, it does not have access to the source code to discover some internal vulnerabilities within the code. Dynamic Application Security Testing cannot point developers to areas of the code that are vulnerable so that they could be immediately fixed.
- Higher Process: There is some requirement that guide the use of DAST and which must be followed clearly and most time some of these requirements on the execution and usage of the application slow down the testing process of DAST. For instance, performing a brute-force attack requires you to try so many user input trials to see if an application can be hacked via the login page. Some scans can take hours or days to complete which can result in a delayed remediation process.
- Shift Right Rule: DAST tool is never deployed or implemented early in the CI/CD pipeline rather it is always introduced toward the end either during testing stages or in production. The reason for this is that you need the application to be run before DAST can work. Waiting for a compiled and deployed application can be risky as any code-related issues may not be easy to fix and may be time-consuming and costly.
- Security Expertise: Dynamic Application Security Testing is mostly used by security experts as there are different features from this tool that you need to learn and carry out some of the tasks like a security expert. If you cannot automate the execution process, then you will have to manually operate the application through application exploration. It is very difficult to scale the application for use.
Types Of DAST Process
Automated Application Vulnerability Scanning: This process is used by security testers who use the tool to scan the web application for vulnerabilities.
Manual Application Security Testing: This is the process of using proxy-based security testing to craft and send requests manually and analyze the response from the DAST dashboard.
Burp Suite: Burp Suite is one of the most popular penetration DAST tools in the world. 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 can help discover vulnerabilities in your application.
Veracode: Veracode is a SaaS application that guarantees your company absolute rest of mind on its application security.
Checkmarx: It is an application that currently helps an organization measure and manage security risk and help remediate security vulnerabilities faster.
Netsparker: It is another DAST tool that currently helps enterprise organizations in achieving their application security status. It helps validate the application’s security and secure thousands of websites.
StackHawk: It is another great tool that helps developers to find security bugs faster and immediately fix them. It provides all the necessary documentation and guides in fixing the issue and provides ways to prevent such issues from re-occurring in the future.
Frequently Asked Questions
Q #1) What is DAST tool?
Answer: A Dynamic Application Security Testing tool is an application security tool that can help you discover vulnerabilities in your applications during runtime which could be in the testing or production environment.
Q #2) What are DAST and SAST?
Answer: Dynamic Application Security Testing is a black box testing that does not have access to the source code but only examines an application as it’s running to find vulnerabilities that an attacker could exploit. While Static Application Security Testing (SAST) is white box testing by accessing the application source code without running.
Q #3) How does a DAST work?
Answer: It can be implemented by simulating malicious attacks on an application and observing the reaction and outcome of the attack if it’s the expected result or not and it can also carry out a scan on an application for any vulnerabilities. It can capture both HTTP and HTTPS requests and the same can be manipulated.
Q #4) Why is DAST important?
Answer: It is a very good security tool that reports fewer false positives. It always provides proof of an exploit on an application through its reporting system to the developers for a closely monitored issue for an appropriate fix and it can be fully integrated with some collaboration tools used in the CI/CD pipeline.
You do not need to know how to write code before you can operate or use a DAST.
Q #5) What is DAST in DevOps?
Answer: It is the process of analyzing an application via the front end of the application to discover any vulnerabilities in the app. This analysis can be in the form of carrying out some simulated attacks on the application at the latter part of the software development life cycle. This attack is done from outside the application with malicious intent.
Q #6) What are examples of DAST tools?
- Burp Suite
- Owasp Zap
- Micro Focus
- HCL AppScan
In your current DevOps, or if you are planning to set up one, then you need to consider a security tool that will not slow down your development. After SAST in the AST market, Dynamic Application Security Testing is widely used by people all over the world. Many organizations currently use DAST while some are planning to adopt the use of DAST in their development environment.
While Dynamic Application Security Testing is good at finding run-time security issues, it can never detect all the vulnerabilities in your application. This tool will never provide you with the extensive coverage of your application that you wish to get.
That is the reason some organizations adopt the use of over one AST tool for their development environment. When you use more than one AST (Application Security Testing) tool you rest assured that a greater amount of security vulnerabilities will be discovered when compared to using just a single security tool.
Further reading =>> What is RASP