The document discusses 5 ways to exploit JTAG (Joint Test Action Group) interfaces to gain unauthorized access or privileges on a system. The 5 techniques are: 1) Accessing non-volatile storage like flash memory via boundary scan, 2) Scraping memory for offline forensic analysis, 3) Patching boot arguments to change how the system boots, 4) Directly patching the kernel by modifying code or function pointers in memory, and 5) Patching a specific process by searching memory for its code and modifying it. While some techniques like memory scraping are slow, others like boot argument patching or kernel patching can be done quickly and provide privileged access. JTAG interfaces provide I/O, execution control, and memory access that enable