Challenge Overview
Can you use your knowledge of format strings to make the customers happy?
Download the binary here.
Download the source here.
Connect with the challenge instance here:
nc mimas.picoctf.net 55122
Solution
Use, nc mimas.picoctf.net 55122, to connect. Once connected it gives three options to choose from:
Breakf@st_Burger, Gr%114d_Cheese, Bac0n_D3luxe
This is a format string challenge, Gr%114d_Cheese, is the only thing that has a format string (%11) in it. Next, these are the choices:
Pe%to_Portobello, $outhwest_Burger, Cla%sic_Che%s%steak
Cla%sic_Che%s%steak has %s in it so by choosing that it gives the flag.
Helpful resources: Specifier table and manual page
Flag: picoCTF{7h3_cu570m3r_15_n3v3r_SEGFAULT_dc...}