The game is about beating a chess that follows a specific rules, like when we move some pawn, it imediately is taken by black pawn, so it basically teleports.
This task comes from the challenge platform flagyard.com and is marked as easy. It is part of the Pwn category and involves exploiting a vulnerable binary.
The challenge involved crafting an XSS payload to extract a flag from an HTML tag, leveraging a vulnerability in the processing of uploaded .xlsx files and exploiting xmlattr vulnerability in Jinja2.