Eun0us/ESPILON-CTF-2026-Writeups
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
cf7da4e7ec
ESPILON-CTF-2026-Writeups/Hardware/Serial_Experimental_00
History
Eun0us b3553ba029 ESPILON CTF 2026 — Write-ups édition 1 (33 challenges)
2026-03-22 19:18:58 +01:00
..
README.md ESPILON CTF 2026 — Write-ups édition 1 (33 challenges) 2026-03-22 19:18:58 +01:00

README.md

Serial Experimental 00 -- Solution

Overview

The challenge provides a split UART interface:

  • TX (read): 1111
  • RX (write): 2222

Goal: recover token and run unlock <token>.

Steps

  1. Open both channels:
nc <host> 1111
nc <host> 2222
  1. Query diagnostics from RX:
diag.uart
diag.eeprom
diag.order
  1. Recover fragments:
  • frag_a_hex=4c41494e -> LAIN
  • frag_b_xor_hex=4056415a525f with xor_key=0x13 -> SERIAL
  • frag_c_hex=3030 -> 00
  1. Build token:

LAIN-SERIAL-00

  1. Unlock:
unlock LAIN-SERIAL-00
  1. Flag is returned on TX.