What is the difference between DAST and SAST?
DAST (Dynamic Application Security Testing) tests a running application from the outside, simulating real-world attacks (like an attacker would) to find runtime vulnerabilities like SQL injection, XSS, server misconfiguration, authentication/authorization flaws etc—without needing source code. DAST is language and framework agnostic unlike SAST, as long as the app is running and accessible via HTTP(S), DAST can scan it.
SAST (Static Application Security Testing) analyzes the application’s source code or binaries early in development to catch issues in logic and structure before the app runs.In summary: SAST = early, code-level, language specific and DAST = later, runtime-level, language agnostic, outside-in.
Using both provides complete security coverage across the development lifecycle.
What is the purpose of dynamic application security testing (DAST)?
Dynamic Application Security Testing (DAST) is designed to identify and remediate security vulnerabilities in running web applications—without requiring access to the source code. The core purpose of DAST is to simulate real-world attacks from an external user’s perspective, uncovering risks such as SQL injection, cross-site scripting (XSS), authentication issues, and other OWASP Top 10 threats.
By scanning the application in its running state, DAST helps organizations to detect security flaws in real time during QA or pre-production stages, ensure applications behave securely under dynamic user interactions, complement SAST and IAST approaches for comprehensive security coverage and comply with security standards and regulatory requirements. When integrated into CI/CD pipelines, DAST empowers DevSecOps teams to continuously test, monitor, and reduce security risks—without slowing down delivery.
What types of vulnerabilities can DAST detect?
Dynamic Application Security Testing (DAST) can identify a wide range of runtime security vulnerabilities in web applications, APIs, and microservices—without needing access to source code.
DAST tools like HCL AppScan Standard simulate real-world attack patterns to uncover issues that malicious users could exploit. Common vulnerabilities detected include: SQL Injection (SQLi) – unauthorized database access, Cross-Site Scripting (XSS) – execution of malicious scripts in user browsers, Command Injection – execution of system-level commands, Authentication and Session Management Flaws – insecure login, token reuse, session fixation, Cross-Site Request Forgery (CSRF) – unauthorized actions triggered from a user’s browser, Unvalidated Redirects and Forwards – attackers redirecting users to malicious sites, API Vulnerabilities – improperly secured endpoints, excessive data exposure, outdated third party components, business logic vulnerabilities and many more.
When should DAST be performed in the SDLC?
Traditionally, Dynamic Application Security Testing (DAST) has been performed during the integration, testing, or pre-production stages of the Software Development Life Cycle (SDLC), once a working version of the application is available. However, with the modern DevSecOps practices and tools like AUDIT (AppScan Unit-level DAST Intelligence Tester), we are now able to shift DAST further left, enabling dynamic testing as early as the code implementation phase.
By running DAST early and often, security teams can identify vulnerabilities before they reach production, reducing risk and remediation costs. Using tools like HCL AppScan Standard, organizations can embed dynamic testing into their development workflows without disrupting speed or agility.
