BSidesSF 2024 Writeups: No Tools (A puzzling Bash challenge)

No Tools is a fairly simple terminal challenge, something for new players to chew on.

I suspect there are several different ways to solve it, but the basic idea is to read a file using only built-in functions from sh.

I personally solved it with the read built-in:

$ read FLAG < /home/ctf/flag.txt && echo $FLAG
CTF{where-are-my-tools}

Another solution that my co-organizer developed used exec:

$ exec < /home/ctf/flag.txt
$ /bin/sh: 2: CTF{where-are-my-tools}: not found

05 May 2024

• BSides San Francisco (2024)
• Capture the Flag

Ron Bowes