Browers can't feasibly stop web pages from talking to private (local) IP addresses
https://utcc.utoronto.ca/~cks/space/blog/web/BrowsersAndLocalIPs [utcc.utoronto.ca]
2019-07-13 05:08
This is a tempting and natural viewpoint, but unfortunately this can’t be done in practice without breaking things. To understand this, I’ll outline a series of approaches and then explain why they fail or cause problems.