The first level target is a board containing an STM32F103, that has all security options available to it enabled. JTAG/SWD is turned off, flash readout is disabled, and the firmware it’s shipped with contains no (known) software vulnerabilities.
The board has 4 challenges, each started by holding a button on the board. It’s up to you to break the target’s security and obtain the flag from each challenge.
Flags are in the format ctf{...}, with 34 uppercase alphanumeric characters where the ... are. The flags are shown in plaintext when you obtain them, and always contain the ctf{} part too, so you never need to add that yourself.
Note:
The target's USB port exposes a single USB UART interface. You can connect to it at 115200 baud using your favourite terminal to see what it's outputting.Warning:
The silkscreen text next to the 3-pin i2c header on revision 1 of the Target board has unfortunately been misprinted. It should be, from top to bottom: - SCL - SDA - GND