Re: [Lynx-dev] Lynx bug when accessing < type items on Gopher protocol domains

[Thomas Dickey]

On Wed, Dec 29, 2021 at 11:51:35PM -0700, Dio9sys wrote:
> Hello!
> 
> I wasn't sure how best to get hold of folks, and wasn't sure if this was
> already known, so please let me know if I'm just adding noise to the crowd
> :)
> 
> On the latest version of Lynx (at least on the Linux version), if you visit
> a gopherhole that has the < item type (specific in gopher+ specs for sound
> files) and follow the link, it will immediately open the link in your
> system-default media player without giving a prompt or showing the full
> file extension to validate that it's a correct file.
> 
> In the example I found, I wrote a simple html file, specified it as < on my
> gopherhole and then opened it on Lynx (on my amd64 Manjaro Linux
> computer).  It immediately tried to open in VLC, which then crashed as it
> didn't know what to do with an html file. It lists as (SND) on the page,
> marking it as a sound file, without checking that it's the supported WAV
> format mentioned in the spec
> 
> If possible, I think it would be a really great idea to have some kind of
> "are you sure?" prompt showing the full file name and extension before
> opening the link, so as to reduce the chance of malware or other such
> nastiness happening.

I suppose - but there are a lot of cases where lynx follows a link
without prompting.  Just in the gopher code, there are 8 types of links 
for which it'll make a connection:

        text/html
        text/plain
        image/gif
        audio/basic (this one)
        video/mpeg
        application/pdf
        compressed-files (via HTFile.c)
        www/unknown

In each case, lynx relies on the mime-type.

Why is this one different?
 
> If you would like an example, you can visit gopher://dio9sys.fun on Lynx
> and go down to the final link on the page, titled Test.
> 
> Thanks for reading all this!
> 
> Regards,
> 
> -Dio9sys, your friendly neighborhood gopher nerd

-- 
Thomas E. Dickey <dickey@invisible-island.net>
https://invisible-island.net
ftp://ftp.invisible-island.net

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