Recent high-profile data breaches have made organizations more concerned about their application security vulnerabilities, which can affect their businesses if their data is stolen. To avoid such application breaches these security vulnerabilities in the applications are to be identified and should be dealt with before it can be exploited. So, adding application security testing methodologies like SAST and DAST to their software development workflows is a very important norm that should be followed nowadays.
SAST and DAST are two different types of application security testing methodologies used to find vulnerabilities in the security of an application that makes it open for attackers to exploit. Static application security testing (SAST) is a method that finds vulnerabilities in the internal functions or workings of an application, more commonly known as white box testing. Dynamic application security testing (DAST) is a method that is performed without a view of the internal source code or application architecture. It uses the same methods of an attacker trying to find the weaknesses. These two testing techniques are an essential part of application security testing. Incorporating only one of the two techniques alone cannot provide a complete picture of the vulnerabilities in an application. So, therefore, to get a comprehensive overview of the security vulnerabilities of an application both SAST and DAST methodologies must be incorporated into the software development workflow.
SAST and DAST are two different testing techniques that yield the best result when carried out in two different phases of the software development life cycle. So, therefore, one of the techniques is carried out at an early stage of the software development lifecycle and the other is carried out at a later stage of the life cycle.
SAST is the technique that is carried out in the early stages of the development lifecycle where the tester will have access to the application’s source code and its design, so any security issues in the application can be found and dealt with before the code enters the QA life cycle. In SAST, since the tests are carried out at an early stage of the life cycle, the issues found will be less expensive and much easier to fix. But a drawback is that since the tests are done with a static code any security issues that are present in the run time environment cannot be detected.
DAST is the technique that is carried out in the later stages of the development lifecycle where the tester has no knowledge of the technologies or frameworks that is used to build the application. The application is tested from the outside in. This type of testing mimics an approach that a hacker uses to attack the application. This technique finds the security vulnerabilities in the application towards the end of the SDLC, so, therefore, fixes for issues found using this technique is much more expensive compared to SAST. The tester will be able to find any runtime vulnerabilities since these kinds of tests are done on a running application in an environment that is equal to the production,
There are various tools available in the market that can be used to conduct these tests. SAST tools are designed to find security flaws in code and provide best practice tips for better coding by providing source code analysis techniques.
Below are a few popular SAST tools:
- Veracode Static Analysis
- Fortify Static Code Analyser
- Checkmarx CxSAST
- SonarQube inspects code and looks for bugs and security vulnerabilities by static code analysis. This is an open-source product and is developed by SonarSource.
- Veracode Static Analysis this SAST tool from Veracode automates security feedback across the development environment and from the CI/CD pipeline, and provides fast static analysis. Before any deployment, a full policy scan is conducted and necessary remedies and suggestions are given as output.
- Fortify Static Code Analyser (SCA) from Micro Focus® gives feedback and remedies by assessing source code and security issues.
- Codacy automates static code analysis, which results in quicker notifications of code coverage, security problems as well as code duplication and complexity of code.
- AppScan provided by HCL (formerly by IBM) is a SAST tool used in the development phase itself, which helps in finding issues and bugs before the production phase.
- Checkmarx CxSAST (CxSAST) is a static analysis tool that can be used in a number of programming and scripting languages which provides the ability to point out security threats in source code.
A DAST tool examines an application from outside when it is running, to crash it just like an attacker does. DAST scanners are not technology dependent. This is because DAST scanners test the applications from outside in. It works with any programming languages and frameworks, both off-the-shelf and custom-built ones.
Below are a few popular DAST tools:
- 1. ZED Attack Proxy or ZAP
- 2. Nikto
- 3. GoLismero
- ZED Attack Proxy or ZAP is a security testing application provided by OWASP and is open-sourced. It scans the application and helps in finding the security vulnerabilities in applications.
- Nikto is a scanner which is open-sourced that perform scans on web servers for bugs and other issues.
- GoLismero is an open-source tool for security testing.
The following are some of the most useful features of this tool:
- It is Platform independence – It is compatible with Windows, Linux, BSD and OS X.
- Python is used to write Golismero.
- simple to use.
Using this tool, the tester can get results of multiple tools with just a single tool. Above mentioned tools are just a few commonly used tools available in the market.
We cannot say that SAST is better than DAST or vice versa. Both are unique and have different approaches to test an application. So, therefore, implementing both the techniques into our SDLC is the best practice to ensure security for our application. As Tim Cook once said
“In the world of cybersecurity,
the last thing you want is to have a target painted on YOU.”
For more information on the topic go to Innovature’s Security testing page