It's Oops PM

Challenge

• CTF: HTB Business CTF 2024: The Vault of Hope
• Name: It’s Oops PM
• Category: Hardware
• Difficulty: Very Easy
• Points: 300
• Description: With the location of the underground bunker secured, the crew embarks on the next phase of their plan: assessing the feasibility of creating an underground tunnel to bypass the super mutant camp. They secure samples of water, soil, and air near the area. Scouring the wasteland for salvageable equipment, they stumble upon a dilapidated research facility where they find a cache of environmental sensors. Examining these sensors, the crew discovers they communicate with a satellite and contain a crypto-processor that encrypts their transmissions. After hand-drawing the diagrams and emulating the silicon chip’s logic with VHDL, they uncover what appears to be a backdoor in the embedded logic that only triggers when a specific input is given to the system. Determined to exploit this, they turn to their tech specialist. Can you connect to the satellite and activate it?
• Objective: VHDL Code Review

Writeup

Reviewing the emulated VHDL, the crypto-processor contains a backdoor branch that bypasses the normal cipher and returns a winning response when the 16-bit input matches the hardcoded constant 1111111111101001.

Spinning up docker container and interacting with it:

nc 94.237.62.130 58623
The input must be a binary signal of 16 bits.

Input : 1111111111101001
Output: 0110001111100001

You triggered the backdoor here is the flag: HTB{4_7yp1c41_53cu23_TPM_ch1p}

Flag: HTB{4_7yp1c41_53cu23_TPM_ch1p}