Hey, man, I need your help. I have some issues with my internet connection, so I send a ticket to my communication service provider, but still no answer. Could you check what theirs admins do instead of fixing issues?

By getting RCE on their server, of course.

palesickpython.student2020tasks.ctf.su:55555/

Added at 16:35: look closely at the Server header and at the page extensions