Intel Management Engine is a proprietary technology that consists of a microcontroller integrated into the Platform Controller Hub (PCH) microchip with a set of built-in peripherals. The PCH carries communication between the processor and external devices; therefore, Intel ME has access to some critical data on the computer, and the ability to execute third-party code allows compromising the platform completely. Researchers have been long interested in such capabilities, but recently we have seen a surge of interest in Intel ME. Intel provides its engineers with the ability to perform ME debugging via JTAG, in addition to allowing third-party developers to debug ISH via DCI (as previously discussed by us at 33с3). Anyone could use the vulnerability we have found to activate JTAG debugging for ME. In our presentation, we will describe the built-in ME debugging mechanism and how to activate it with the help of this vulnerability.