CSICTF-Writeups/Miscellaneous/BroBot

BroBot

The main idea finding the flag is just using Bot to get the flag.

Step-1:

I tried /about to get information about the bot and got this:

CTF - https://ctf.csivit.com/
Our Team - https://ctftime.org/team/77170/
Homepage - https://csivit.com/
Contribute - https://github.com/alias-rahil/speakingbot.git/
CTF Support - https://discord.com/invite/9wHPB2B/
BoT Support - @alias_rahil

Step-2:

I used /text2voice. I linked to the source of the bot. It writes our text as arg for echo in a bash script. Then pipes the script's output to espeak to get the sound.

Step-3:

I got this from writeup to execute.

fs = open(f"/home/ctf/{update.message.from_user.id}", "w")
    fs.write(f"echo '{text}'")
    fs.close()
    os.system(
        f"su ctf -c 'sh /home/ctf/{update.message.from_user.id} | espeak -w /home/ctf/{update.message.from_user.id}.wav --stdin'"
)

Then a simple ';cat flag.txt;' gives us the answer.

Step-4:

Finally the flag becomes: csictf{ai_will_take_over_the_world}