The two websites which are facing the issues are: lanla.pl , shebella.pl
I have been using let's encrypt for years now, 3-4 days ago on 2 of my website strange issues started happening. People who are trying to visit my page are getting SSL certificate errors.
For PC visitors who have avast, they are getting blocked by avast with "URL:blacklist" infection error, people who are trying to browse with android or google chrome mobile are getting errors like: NET:: ERR_CERT_AUTHORITY_INVALID or SSL_UNTRUSTED
My hosting company is trying to find out what the issue is but they are unable as everything with certificate seems to be fine.
I checked my websites via let's debug, virus total, and many other sites, everything seems smooth:
Something is probably intercepting connections to your website and serving an improper certificate. Please tell us what the name of the CERT_AUTHORITY in that error is. Click on "more info, show certificate" or something like that.
Yes, I am aware that the issue started happening 4 days ago, today I sent requests to avast for them to check, it might take up to a few days to receive a response.
I am not able to replicate the error on my side, I am asking some other person to try and get it, however after clicking "more info" (number 1 inthe screen) it redirects to a page which shows mutiple ways of fixing it, but not a specific certificate name etc. Just a dozen of links on how to fix certain issues.
When clicking on "advanced" this is number 2 in the screen, it says some default stuff about connection possible being interceptied etc.
On Android you can solve it by using the long chain. (Which is the default if you use Certbot)
On computers, you have to make your clients install the ISRG Root X1 root certificate. Or use a recent version of Firefox. Or switch certificate authority for one that has better support for old clients.
Seems a little bit too complicated for me, I am using let's encrypt as it is built in via my hosting company in their direct admin panel. I have no clue whether they have all of the certbot updates on the cloud servers they provide. I will forward this reply to them, maybe they can check if they are up to date with everything.
However this is all very strange as none of this issues appeared before 4 days ago, nobody reported anything.