Challenge Description
Hmm… the challenge name and description is quite vague. Let’s run the command given when I launched an instance to understand what exactly is going on.
Getting the Flag
Running nc saturn.picoctf.net 53781 displayed the following string:
'picoCTF{gl17ch_m3_n07_' + chr(0x39) + chr(0x63) + chr(0x34) + chr(0x32) + chr(0x61) + chr(0x34) + chr(0x35) + chr(0x64) + '}'
What does
chr()do?From a previous challenge (PW Crack 2), I learnt that the
chr()function in Python returns the character that represents the specified unicode.For example, chr(97) allows us to get the character that represents the unicode 97.
So I proceeded to create a very simple Python script named “solve.py” to display the flag.
flag = 'picoCTF{gl17ch_m3_n07_' + chr(0x39) + chr(0x63) + chr(0x34) + chr(0x32) + chr(0x61) + chr(0x34) + chr(0x35) + chr(0x64) + '}'
print(flag)Running python solve.py displayed the flag.
Flag
picoCTF{gl17ch_m3_n07_9c42a45d}