Dynamic application security testing (DAST) is best described as which of the following?

Dynamic application security testing (DAST) is best described as a test performed on an application while it is being executed in memory. This involves assessing the application’s security posture during its runtime, which means evaluating how it behaves under actual conditions as it processes requests, interactions, and transactions. DAST tools simulate attacks against an application to identify vulnerabilities that may only be apparent when the application is actively running.

This methodology focuses on measuring the application's response to real-time interactions and helps in spotting issues such as input validation flaws, session management vulnerabilities, and other runtime concerns that static testing cannot uncover since it analyzes the code without execution. Such testing is crucial for discovering security weaknesses in live applications and ensuring they are managed effectively before they can be exploited by malicious actors.

While the other descriptions might pertain to different types of testing practices, they do not encapsulate the essence of DAST as effectively as the execution in memory does.