I can see your local web servers

I'm interested in this because I don't fully understand the consequences here. I'd like to gain a deeper understanding through some concrete examples.

With the PHP CLI, I can run:

    php -S localhost:8000

With Python3, I can run:

    python -m http.server 8000 --bind localhost

The demo fails for me in both cases, even though a request to localhost:8000 is sent. (EDIT: The server log in the terminal window does show that the request arrived at the local server).

My question is: What is the risk of running one of these servers and then visiting some random web page?

> My question is: What is the risk of running one of these servers and then visiting some random web page?

It depends on what you're exposing on those ports. If it's something sensitive, stop. Any web page can run javascript and as such, any web page has access to every port and service that your machine has access to ... because at that point, the web page is a program running on your machine with full network access.

However, this entire "vulnerability" makes no sense to me. Even if I'm running something on my machine or local network, I am not going to rely on the firewall as a security mechanism. That is profoundly stupid and is well known to be profoundly stupid. So all those servers, including the ones I am creating and running, will have their own security mechanisms. So you can ping my server? So what?