Pico CTF

Format Strings 0

Description

Can you use your knowledge of format strings to make the customers happy? Download the binary here. Download the source here.

nc mimas.picoctf.net 52607

Hints

  1. This is an introduction of format string vulnerabilities. Look up "format specifiers" if you have never seen them before.
  2. Just try out the different options

Solution

picoCTF{7h3_cu570m3r_15_n3v3r_SEGFAULT_74f6c0e7}

CLI

kappa@kappa-Aspire-Z5600:~$ nc mimas.picoctf.net 52607

Welcome to our newly-opened burger place Pico 'n Patty! Can you help the picky customers find their favorite burger?
Here comes the first customer Patrick who wants a giant bite.
Please choose from the following burgers: Breakf@st_Burger, Gr%114d_Cheese, Bac0n_D3luxe
Enter your recommendation: Gr%114d_Cheese

4202954_Cheese
Good job! Patrick is happy! Now can you serve the second customer?

Sponge Bob wants something outrageous that would break the shop (better be served quick before the shop owner kicks you out!)
Please choose from the following burgers: Pe%to_Portobello, $outhwest_Burger, Cla%sic_Che%s%steak
Enter your recommendation: Cla%sic_Che%s%steak

ClaCla%sic_Che%s%steakic_Che(null)

picoCTF{7h3_cu570m3r_15_n3v3r_SEGFAULT_74f6c0e7}