For about two months I have been unable to reach a website I frequent. Firefox displays this message:
Did Not Connect: Potential Security Issue
Firefox detected a potential security threat and did not continue to xxxxx.com because this website requires a secure connection.
What can you do about it?
xxxxx.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site.
The issue is most likely with the website, and there is nothing you can do to resolve it. You can notify the website’s administrator about the problem.
Websites prove their identity via certificates. Firefox does not trust this site because it uses a certificate that is not valid for xxxxx.com. The certificate is only > valid for the following names: *.a6z-dns.ovh, a6z-dns.ovh
Error code: SSL_ERROR_BAD_CERT_DOMAIN
When I view the certificate, I see this:
The website's certificate is not issued by "Certainly", and the name "a6z-dns.ovh" is not related to the domain.
This is on my primary workstation. It happens with any browser, even newly install browsers (Edit: Firefox, Chromium, Edge, Konqueror, Opera, Falkon, Midori.) There is not a problem viewing the website from inside a VM on my workstation and other machines/devices on the same network. (Edit: This is not a corporate environment and I do not use any OVH Cloud products or services.)
I've checked my DNS setup, rebooted the workstation, tried everything I can think of, but nothing helps. Does anybody have any idea what the problem might be?
Edit: More information based on comments below:
Software installs before the problem began: openSUSE updates, packman updates, plexmediaserver, antiword update from KDE-Extra, recoll update from KDE-Extra.
I have never even heard of OVH Cloud dns. The dns servers I use are 10.0.0.10 (my own server for private network) and google's servers.
I am not the owner or operator of the web server in question. I didn't give the name because the last time I posted this question it got moved to meta where everybody just said "It's not our problem". If you need to know, the website is stackoverflow.com. (And this revelation better not get this question moved to meta again!)
This is obviously something that only effects this one workstation.
