: The year was defined by massive patches for widespread issues, such as the PrintNightmare vulnerability and the Log4Shell emergency patches .
Before the JTAG chain is enabled, the patched module requires a 128-bit AES-CMAC token derived from a device-specific secret burned into an e-fuse array. Without this token, the debug port remains electrically disconnected at the PHY level. juq016 2021 patched