Dynamic application security testing (DAST) scanners are crucial to the security and integrity of web applications, APIs, and cloud infrastructures. They scan your applications to find hidden vulnerabilities and offer detailed reports with instructions to fix identified vulnerabilities.
What’s more, leading DAST tools allow you to run compliance-specific scans, such as a PCI-DSS, to discover non-compliance areas.
But what is DAST exactly, how does it work, and what are the best DAST tools available in the market? Let’s find out.
What Is DAST and How Does It Work?
Dynamic application security testing (DAST) is an application security testing methodology in which a running application is tested to identify vulnerabilities.
DAST doesn’t have access to the source code of an application. So DAST detects security vulnerabilities by carrying out simulated attacks.
The DAST approach evaluates a running application from outside by attacking the application as the hackers would do. The application’s responses to these simulated attacks are analyzed to determine if the running application is susceptible to various actual web application attacks.
In a sense, DAST tools perform automated penetration testing of your web application to identify security weaknesses in the application.
In other words, a DAST tool works like a security guard you appointed to protect your home. This security guard is more than just an ordinary security guard. Instead, the guard tries to break into your house by breaking locks on the doors or windows for assessment.
After doing the assessment, the guard lets you know how they were able to enter your home so that you can strengthen your house’s security to avoid further such incidents.
The following is how a DAST scanner typically works:
Scanning the Application
A DAST tool interacts with a running application to complete vulnerability scanning. In the process, the DAST tool assesses application security posture. The process can include finding potential input fields within an application, forms, API endpoints, etc.
Carrying Out Simulated Attacks
The DAST tool performs simulated attacks to test application security for common web application threats such as SQL injection, cross-site scripting (XSS), and various other web application injection attacks.
Identifying Vulnerabilities
After carrying out simulated attacks, the DAST tool analyzes the application’s responses to determine if any weakness or vulnerability has been exposed during the attacks. If it detects critical vulnerabilities, it will mention them in the report along with the severity of the security vulnerabilities.
Sending Report
The DAST tool generates a detailed report on its findings, including identified vulnerabilities and recommendations for remediation. Security professionals can use this report to address security concerns and improve application security.
A good DAST tool leverages both automatic pen testing and manual testing techniques to conduct a thorough security assessment of a web application to identify potential vulnerabilities.
Benefits of DAST Scanners
The following are key benefits of using a DAST solution to improve the security of your web application:
- It will identify various runtime vulnerabilities, which can be detrimental to your web application and company if exploited
- A DAST tool acts as an actual hacker. So it can discover vulnerabilities or security weaknesses often missed by other security testing methods
- It can help your security experts and development team find vulnerabilities outside your application’s source code and in third-party interfaces
- DAST is the only security testing method that is not programming language specific. So you can test any web application, irrespective of its programming language
- It can run compliance-related scans to help you comply with leading data security regulations
A DAST scanner discovers a broad range of vulnerabilities and security weaknesses, including input/output validation issues, miss configurations, authentication errors, and many other runtime issues.
And it is easy to combine DAST with other web application security testing methods, such as SAST.
How DAST Is Different Than SAST
Static application security testing (SAST) is a white-box app security testing methodology in which security professionals test a web application from the inside for known vulnerabilities.
Deployed in the early stages of the software development lifecycle (SDLC), SAST evaluates a range of static inputs, including the application’s source code and documentation (requirements, design, specifications, etc.).
As a SAST tool has full access to an application source code, it can identify where a vulnerability exists. Also, it can discover vulnerabilities in code fragments that you have written but not deployed or linked with the main application.
On the other hand, DAST tools perform security tests on a running application from outside to identify vulnerabilities or security weaknesses in the web application. One doesn’t require access to the source code of an application to do dynamic application security testing.
Here are the key differences between DAST and SAST:
- DAST tests a running application from outside by carrying out simulated attacks. And SAST tests a web application in the early stage of the software development lifecycle by evaluating its source code, configuration files, and other static artifacts.
- DAST focuses on the application’s front end, such as its interaction with users, API endpoints, and other systems, to find the application’s weaknesses, such as runtime issues or misconfigurations that hackers can exploit. But SAST analyzes the application’s source code and finds vulnerabilities within the codebase.
- As DAST identifies vulnerabilities and security issues at the later stage of the software development lifecycle, it is often expensive to fix those vulnerabilities. The types of vulnerabilities SAST discovers are inexpensive to remediate.
- DAST tends to give fewer false positives than SAST does.
To your question, SAST vs. DAST: what’s better for application security testing, the answer is both. By combining these two app security testing methodologies, you can comprehensively assess your web application security.
Picking the best DAST scanner can be tricky as numerous options are available. We have researched and prepared a list of the best DAST solutions to save you time.
Probely
Probely is a trusted DAST scanner to automate and scale web applications and API security testing. Its vulnerability scanner helps you identify around 30,000 vulnerabilities and provide a detailed report to fix them.
Its headless-Chrome based spider navigates through a web application like a human. Its spider crawls every corner of your app, clicking links and filling out forms with the correct context to offer the industry’s leading coverage.
Key Features:
- Free from false-positive (-0.06% in 2022)
- Multiple scanning options, including customizable scanning, scheduled scanning, and scanning behind the firewall
- Authenticated scan to scan applications that rely on SSO and OpenID Connect
- Easy integration with your application using its add-on or full-featured API
You can use it to fulfill web security compliance requirements by generating detailed requirement reports and showing those reports as evidence of compliance. You can easily integrate Probely with CI/CD tools, issue trackers, and messaging apps.
Invicti
With its unique DAST plus interactive application security testing (IAST) approach, Invicti detects vulnerabilities and security weaknesses that other DAST tools may miss. In order to make sure that no vulnerability or security weakness goes unnoticed, it combines signature and behavior-based testing.
Key Features:
- Ability to run vulnerability scans on websites, web applications, and APIs
- A complete and updated inventory of all of your websites, web applications, and APIs
- Advanced scanning technology, enabling you to scan script-heavy websites
- Ability to scan passwords and MFA-protected areas
- Deployment in multiple environments, including cloud, on-prem, and everything in between
- Broad coverage for vulnerabilities, including SQL injection, Server-side request forgery, XSS, Out-of-band vulnerabilities, and more
- Integration with 50+ tools, including CI/CD, issue trackers, collaboration tools, and more
Invicti identifies all of your open-source components and detects which components are vulnerable. It helps you track the security posture of each application over time.
Indusface WAS
Indusface WAS is one tool that offers you functions of DAST, malware scanning, and penetration testing.
Key Features:
- A broad range of vulnerability coverage, including SANS25, OWASP Top 10, WASC-classified threats, and zero-day threats
- Bundled protection for mobile, web, and APIs
- Zero false claim guarantee
- Ability to create an inventory of public-facing web assets (domains, subdomains, IPs, mobile apps, data centers, and site types)
- Detection of web defacement and malware infection
- Vulnerability assessment and penetration testing (VAPT) on the identified assets with a single click
Its automated vulnerability scanner checks all the areas, including single-page applications (SPAs), script-heavy websites, password-protected areas, complex paths and multi-level forms, and unlinked pages.
As automated scanners cannot detect all vulnerabilities. Indusface WAS also comes with a manual pen-testing feature that allows security experts to identify business logic vulnerabilities
Rapid7 InsightAppSec
InsightAppSec by Rapid7 is another powerful DAST tool to automatically assess your web application with fewer false positives and missed security weaknesses. Small or big, you can manage the security assessment of your application portfolio effortlessly with InsightAppSec.
Key Features:
- Protection from over 95 attack types.
- Attack replay feature to make remediation easier
- Ability to export actionable reports in an HTML format
- Option to tailor your reports to several compliance regulations, such as HIPAA or PCI-DSS
- Cloud and on-prem scan engines.
- Option to schedule scans and set scan blackout periods
- Ability to scan vulnerabilities due to misconfiguration
- Option to run multiple scans simultaneously at no additional cost
- Easy integration into dev workflows
The universal translator in InsightAppSec increases your application coverage area. Also, It offers custom checks to address issues and risks your app environment faces.
A good thing about InsightAppSec is it enables you to collaborate with speed. Its rich reporting and integrations make it quicker to inform compliance and development stakeholders.
StackHawk
If you’re looking for a flexible yet powerful DAST tool, StackHawk is the right choice. It is language agnostic and runs anywhere on any platform.
StackHawk is designed to focus on runtime and pre-production application security testing. It allows your team to actively test your application as part of their CI/CD workflows.
Key Features:
- Ability to test all APIs, including REST, SOAP, GraphQL, and gRPC APIs
- Custom test scripts to cover specific scenarios for your web application
- Prioritized scan results to help identify critical issues easily
- Recreation and validation of findings with StackHawk’s cURL generator
- Optimized scanner to quickly find vulnerabilities.
- Ability to run in any CI/CD
- Technology-Specific API Scan Configs
- User-friendly web application
StackHawk offers detailed App Request & Response data, developer-friendly explanations, and resources to investigate issues easily and efficiently. It offers four packages for users: Free, Pro, Enterprise, and Custom.
SOOS DAST
SOOS DAST is a multi-award winning dynamic application security testing tool to find web application vulnerabilities and security weaknesses. The containerized solution runs in your environment with Docker. It allows you to manage security issues via a unified web dashboard shared with SOOS SCA.
Key Features:
- Scan web apps and APIs defined by OpenAPI, SOAP, or GraphQL
- Unlimited DAST domain scanning
- CI/CD integrations like Azure DevOps, AWS CodeBuild, GitHub Actions, and CircleCI
- SOOS SCA for OSS vulnerability scanning and license management
- A broad scan coverage, including SQL Injection, Missing Security Headers, Security Misconfigs, Cross-site scripting, and much more
- Ability to push issues to GitHub’s Security Panel
- Open Source License Management
SOOS DAST leverages Industry-Standard Open Source ZAP Scanner with added features to offer your application broad security coverage.
Veracode Dynamic Analysis
Veracode Dynamic Analysis is a single platform that allows security and development teams to find and fix runtime vulnerabilities in web apps and APIs.
Key Features:
- A cloud-native engine that constantly improves audit and scan capabilities
- Customize scan (with easy-to-configure parameters) to save time and reduce errors
- Application and APIs scanning behind a firewall
- Detailed reports that can be integrated with popular ticketing systems
- Flexible scan parameters settings such as browser limiting and authentication support
Veracode DAST has a <5% false positive rate.
AppCheck
AppCheck is a comprehensive security testing platform that allows you to evaluate each layer of external IT systems for vulnerabilities in one solution. It enables you to test all facets of your application and network targets.
Key Features:
- Full OWASP vulnerability coverage, including XSS, injections, zero-days, plus 100,000+ known security flaws
- n-depth automated testing to do ad-hoc testing, scheduled scanning, and continuous security testing
- Ability to deliver automated vulnerability testing through your build servers, including MS Azure DevOps, Jenkins, and Team City
- A thorough scan of your API, including WSDL, Swagger, and Graph QL endpoints
- Ease of use—a single click generates professional penetration testing style reports with detailed descriptions of vulnerabilities and remediation steps.
AppCheck also allows you to do vulnerability management through your in-house ticketing systems, such as JIRA.
Checkmarx DAST
Checkmarx DAST is a powerful web security scanner available in the Checkmarx One application security platform. It provides you with an insightful view of the overall risks of your applications through a single dashboard. Checkmarx DAST supports various integrations and languages.
If you’re a fan of open-source software, you can explore these open-source web security scanners.
Conclusion
Web application attacks are skyrocketing. Hackers target web apps and APIs to steal sensitive data or deliver malware. So it becomes crucial to choose one of the best DAST scanners to assess your web application, API, or cloud infrastructure to detect and fix security vulnerabilities.
Additionally, you should learn more about web application security to enhance your app security and protect your application from threat actors.