Security consideration: math symbols in an exotic IP address format in a phishing mail

[Magnus Bodin ☀]

On Sun, May 17, 2020 at 12:06 PM Stephane Bortzmeyer via Unicode
<unicode at unicode.org> wrote:
>
> On Sun, May 17, 2020 at 01:43:17AM +0200,
>  Marius Spix via Unicode <unicode at unicode.org> wrote
>  a message of 15 lines which said:
>
> > This worked for both Firefox and Chrome.
>
> Also in a terminal with ping, so I suspect this is handled by lower
> name resolution libraries.

Yes, It is an old legacy from BSD libraries that has been inherited.
Actually, it accepts various formats (previously even more than 32 bits.

I illustrated this with a website here 1998:

https://x42.com/active/ip32.mpl?host=archive.org

Nowadays the 40, 48 and 56-bit ones are blocked at least in Chrome.

-- magnus