CyberQuest 2025 - ChassisNumber

Description

We found an unknown vehicle in the junkyard without chassis number. Maybe it’s stolen. Do you have any idea to find it somehow?

Challenge difficulity: hard

Metadata

• Filename: candump.txt
• Tags: can

Solution

I searched for the known parts of the flag in hex.

The message id 6B4 is the important one:

$ cat candump.txt | grep '6B4#' | cut -d' ' -f3 | sort -u
6B4#0000000000435132
6B4#01357B6334726964
6B4#02336E746974797D

The flag is: 435132357B6334726964336E746974797D

Flag: CQ25{c4rid3ntity}