Memory leaks are errors that occur when a program does not release memory that it has allocated, causing the system to run out of memory and slow down or crash. Memory leaks cannot be detected by structure-based testing techniques, which are based on the code structure and logic. Structure-based testing techniques can only find errors that are related to the control flow, data flow, or logic of the program. For example, they can find errors such as features that are only partially implemented, data structures that are used before initialization, or division by zero. To detect memory leaks, you need dynamic analysis tools that monitor the memory usage of the program during execution. You can find more information about structure-based testing techniques and dynamic analysis tools in A Study Guide to the ISTQB® Foundation Level 2018 Syllabus, Chapter 4, Sections 4.2 and 4.31.