JShell get a JavaScript shell with XSS. The Java Shell tool is an interactive tool for learning the Java programming language and prototyping Java code.

JShell Usages

Run shell.py and it will automatically try to detect your IP address, default LPORT is 33.

As you can see the payload has been generated and now all you have to do is to deliver this payload to the victim.

Also ReadUDP2Raw Tunnel – A Tunnel which Turns UDP Traffic into Encrypted UDP/FakeTCP/ICMP

As soon as you do that, you will get a JS shell over netcat where you can execute your JavaScript code in victim’s browser as soon as the injected page is open.
Here’s a screenshot:

Credit: Rodolfo Assis