SAST vs. DAST vs. IAST

In Application Security (AppSec) testing, SAST, DAST, and IAST are three cornerstone methodologies for identifying vulnerabilities within software applications. Each of these methods offers a different approach to identifying security vulnerabilities at different stages of the Software Development Lifecycle (SDLC). Understanding the differences between SAST, DAST, and IAST is crucial for effectively integrating them into a comprehensive AppSec program.

What is SAST?

Static Application Security Testing (SAST) is a type of security testing that examines a program’s source code, binary code, or bytecode to detect vulnerabilities without executing them. This method enables developers to detect and address security vulnerabilities at an early phase of the software development lifecycle. This helps automatically identify and minimize security issues that could potentially compromise the system’s security before the software is deployed. These issues include input validation errors, insecure dependencies, cross-site scripting vulnerabilities, potential backdoors, and injection flaws. It is often referred to as white-box testing, as it requires access to the application’s internal source code and design.

Top SAST Tools

What is DAST?

Dynamic Application Security Testing (DAST) method is used to detect vulnerabilities in web applications by simulating attacks on a running application. Unlike static analysis, which assesses code in a static state, DAST simulates an attacker’s perspective by evaluating a program externally. This approach is effective in detecting runtime issues like session management errors, authentication and authorization errors, and other vulnerabilities that may not be detected through static analysis. It is also called black-box testing because it does not require access to the internal source code, allowing real-world testing scenarios.

What is IAST?

The Interactive Application Security Testing (IAST) method combines aspects of SAST and DAST to identify vulnerabilities in applications during their runtime. This method allows developers to monitor application behavior, data flow, and execution paths, providing real-time feedback on potential security vulnerabilities. It offers detailed vulnerability insights while minimizing false positives, as it has a deeper understanding of the application’s runtime context. This makes it easier for developers to comprehend and remediate security vulnerabilities effectively and efficiently.

Key Differences Between SAST, DAST, and IAST

Aspect	Static Application Security Testing (SAST)	Dynamic Application Security Testing (DAST)	Interactive Application Security Testing (IAST)
Methodology	Analyzes source code, bytecode, or binary code for security vulnerabilities without executing the program Uses predefined security rules to detect vulnerabilities	Analyzes the application during runtime from an external perspective Identifies security issues by simulating attacks on a running application	Combines static and dynamic analysis methods Monitors application behavior and data flow during testing Analyzes code execution paths and then provides detailed vulnerability insights
Use Cases	Commonly used during the early stages of development to identify and address vulnerabilities Continuous integration environments Code review and Quality Assurance (QA) processes	Usually conducted in staging or Quality Assurance (QA) environments before production External security assessment and penetration testing Validating vulnerability fixes and security patches	Used during automated testing or Quality Assurance (QA) testing phases Integrating security into DevOps and agile methodologies Real-time security assessment in complex, dynamic applications
Advantages	Identifies vulnerabilities early in the development cycle Does not require a running application Can be automated within CI/CD pipelines Enhances code quality and security compliance Educates developers on secure coding practices	Identifies vulnerabilities in running applications Effective for detecting runtime issues and configuration errors that static analysis might miss Simulates real-world attacks Can test applications without access to source code	Identifies vulnerabilities in real-time during testing Bridges the gap between SAST and DAST Can detect a wider range of issues by combining static and dynamic analysis Seamlessly integrates into the SDLC, causing minimal disruption Provides accurate code-level insights, reducing false positives
Disadvantages	May produce false positives or negative Requires access to source code Less effective for identifying runtime issues	Can only identify vulnerabilities that are exploitable via HTTP/HTTPS Requires a fully deployed application Might miss issues detectable only by inspecting the source code	Requires integration with the application’s runtime environment Potentially more complex setup than SAST or DAST May impact the performance of the application during testing
Output	Detailed report of potential security issues in the code, including severity levels and recommendations for remediation	Vulnerabilities report discovered during runtime, including where the application is susceptible to attack	Comprehensive report combining insights from both static code analysis and dynamic testing, including detailed information on how vulnerabilities can be exploited and remediated
Integration in DevSecOps	Often integrated at the coding or pre-commit stage in the CI/CD pipeline	Typically integrated during the later stages of the CI/CD pipeline, such as during integration testing or pre-deployment	Flexible integration points, often during automated testing phases or in pre-production environments, allow continuous monitoring and assessment
Ideal For	Developers looking to identify and fix security issues during the coding phase	Security teams that validate the security posture of applications before production deployment	Organizations that want a more thorough and real-time analysis throughout the development process

Which One to Choose: SAST, DAST, or IAST

Choosing the right Application Security (AppSec) testing methodology depends on the particular requirements of the project, its current development stage, and its available resources. SAST is invaluable for detecting vulnerabilities early in the development phase, while DAST excels in revealing runtime issues. IAST, on the other hand, delivers a comprehensive analysis by combining elements of both static and dynamic testing methodologies. By understanding the pros and cons of each method, organizations can enhance the security of their applications throughout the development lifecycle.

Check out the related blogs:

• What is DevSecOps and How Does It Work?
• Top 20 DevSecOps Interview Questions
• How to Become a DevSecOps Engineer?
• Introduction to DevSecOps Maturity Model
• Is a DevSecOps Career Right for You?
• DevOps Vs. DevSecOps
• What is Compliance in DevSecOps?
• 10 Skills DevSecOps Engineers Must Master
• CI/CD Pipeline Security in DevSecOps
• Why Choose DevSecOps Practical Course with InfosecTrain?
• Top DevSecOps Interview Questions
• Top SAST Tools in 2025

How Can InfosecTrain Help?

Individuals interested in learning more about these security methods can enroll in InfosecTrain’s Practical DevSecOps Training course. The course equips participants with hands-on experience applying security measures in a DevSecOps environment. This course emphasizes practical applications and allows learners to work on live projects and use case studies.

TRAINING CALENDAR of Upcoming Batches For DevSecOps

Start Date	End Date	Start - End Time	Batch Type	Training Mode	Batch Status
13-Sep-2025	12-Oct-2025	19:00 - 23:00 IST	Weekend	Online	[ Open ]	Enroll Now