Before#

This is my first time writing English Writes up , apologize my poor English xDD

Story began after TVE Joint College Entrance Examination ended , LemonTea ask me if I want to create a challenge to NHNC.

Hence , the gueesy Challenge borned.

dkri3c1_love_cat#

Actually, this challenge is very guessy xD , the main reason is that I want my Challenge won’t be solved easily by AI

OK,Let’s talk about solution , when you connect to the website , you will find that you can use parameter img to read file

OK, And we try if it have the LFI with payload ../

It will return 500 Internal Server Error

Hence, we can guess this challenge is to read file with LFI , after a lot of guessy , you can use ....// to get last directory , and our target is find where the flag file is.

according to the hint , we need to find the directory includeing app.py, just fuzzing the path , and you will find ....//....//app.py will get the source code

try to use the path ....//....//flag.txt and you will get flag!

flag{dkri3c1_Like_Cat_oUo_>_<_c8763}

unintended solve is that I find someone readfile with absolute path , if you are guessy king , you can guess that the directory name is app and flag is in the flag.txt