CyberQuest 2025 - Drivetrain

Description

Something ridiculous happened with this car. Examine the logs.

Challenge difficulity: medium

Metadata

• Filename: candump.txt
• Tags: can

Solution

I tried to find the known characters of the flag in hex in the dump (C - 43, Q - 51).

The messages with the id 000 are the important ones:

$ cat candump.txt | grep '000#' | cut -d' ' -f3 
000#DEADBEEFCAFE0043
000#123456789ABC0051
000#1240000812480032
000#F243522812480035
000#CAFEBABEDEAD007B
000#1248124812480064
000#0000000000000064
000#0102030405060030
000#56789ABCDEFA0073
000#BEADF00DFACE005F
000#FFFFFFFFFFFF0030
000#FEEDFACEBADC006E
000#BEADF00DFACE005F
000#B00000BADC0D0063
000#7E7E7E7E7E7E0034
000#112233445566006E
000#BAADBEEF0000007D

The last bytes give the flag: 435132357B646430735F306E5F63346E7D

Flag: CQ25{dd0s_0n_c4n}