After a new OpenWRT flash on my router my device browser is suddenly warning about certificate errors (SSL_ERROR_BAD_CERT_DOMAIN). It is far from every site though but all of a sudden I'm getting these browser warnings on several websites, which didn't happen before flashing to OpenWRT.
It seems to be related to the domain names. Screenshot:
I don't use antivirus products and the issues began after switching to a newly flashed router with OpenWRT, so I suspect it is related. I'm fairly security conscious and I doubt it's a MITM, I'm pretty sure it's caused by something in the configuration.
Not sure if incorrect time settings can cause BAD_CERT_DOMAIN errors but both my laptop device and the OpenWRT router are configured to the correct time. The certificates haven't expired, either.
Official OpenWrt images do not affect/interfere the SSL traffic/certificate handling.
Doublecheck if you receive these errors from another connected mobile device as well ... and please provide more information: Where did you download/flashed which image? Any special plugins activated? Which URL did you use for testing?
The image I flashed was this one. (Firmware downloads really should be available with https btw!)
I tried it on my phone, and it produced the same error. HOWEVER, I also disconnected from the OpenWRT router and used my mobile connection and it produces the same error when bypassing my home connection. So this indicates there's something wrong on their end, and because I've been receiving the error on different websites it may be related to the certificate authority (Digicert, in this case) ?
Edit: also tried it on a Wireguard VPN connection and it also produces the error. So I've essentially tried it on 3 different connections and 2 different devices, 3 different browsers.
It does, because ssl enabled "wget" (ustream) implementations aren't part of the default preinstalled package set (for size reasons and other side effects, such as certificate complaints for self-signed 'invalid' access to the router's webinterface).