Challenge

A chatbot (VULNBOT) asks you to submit the flag. It rejects every answer you give.

Approach

The bot is programmed to reject what you claim is the flag and accept what you claim is not. After reading the source/description carefully:

  • Submitting something that looks like a flag gets rejected.
  • Telling the bot “the flag is y” (or any non-flag string) causes it to accept and reveal the real flag.
  • The actual flag is embedded in the bot’s response upon “successful” submission.

This is a reverse-psychology / logic puzzle. The answer to submit is y.

Flag

boroCTF{0nLinE_C@ts*}