Image Copy Resampled - Cookie Arena
Description:
The lab simulates the image resize function using the GD library. However, it has something quite serious flaw. Read the file /flagXXXX.txt stored in the root directory '/’ to find the flag.
FLAG FORMAT: BKSEC{XXXX}
Source code: https://battle.cookiearena.org/arenas/bkctf-2023/battle/image-copy-resampled/download
Challenge cho source code có cấu trúc như sau