Challenge 19: Glitch Cat

Description

Our flag printing service has started glitching!
$ nc saturn.picoctf.net 53933

Tags

Beginner picoMini 2022 General Skills nc shell python

Points

100

Solution

If we connect to the server, we get the following output:

$ nc saturn.picoctf.net 53933

'picoCTF{gl17ch_m3_n07_' + chr(0x61) + chr(0x34) + chr(0x33) + chr(0x39) + chr(0x32) + chr(0x64) + chr(0x32) + chr(0x65) + '}'

We can see that the flag is being printed, but there are some characters missing. We can fix this by replacing the chr() function with the actual characters. We can use the python3 command to do this:

>>> print('picoCTF{gl17ch_m3_n07_' + chr(0x61) + chr(0x34) + chr(0x33) + chr(0x39) + chr(0x32) + chr(0x64) + chr(0x32) + chr(0x65) + '}')

'picoCTF{gl17ch_m3_n07_a4392d2e}'

Flag

picoCTF{gl17ch_m3_n07_a4392d2e}