Kaspersky antivirus does not recognize letsencrypt certs

I recently switched to Kaspersky free antivirus for Windows 7.

Kaspersky does not recognize the Letsencrypt SSL certificates or says the date is too old even when it is current.

Kaspersky then steps all over the SSL and when you go to view the certificate in the browser Kaspersky shows up as the SSL certificate good to 2020

Kaspersky is a pesky antivirus - and no love is lost on it right now

It does not bring up mail - which has valid letsencrypt SSL certs - without going through exclusions every time

Has anyone else seen this or know how to fix it short of getting rid of Kaspersky Antivirus ??

Hi @unioncos

what's your domain name?

Perhaps Kaspersky creates an own certificate and uses that. So the SSL-connection is broken.

As a user, if you want to continue using Kaspersky, but not have it intercept your SSL/TLS connections, this might help.

As a website operator, though, there’s not much you can do, except to double-check that your configuration is valid generally - as an antivirus or similar might encounter one error (such as an incomplete certificate chain, which browsers might ignore in some circumstances) and present it to the user as a totally different error.

Check out this older thread…

Been there and done that.

Might Help

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Using ESET Smart Security there was no problem and the sites produce an A rating at SSLLabs

Yes - Kaspersky created its own SSL certs for the browser

I turned off the Kaspersky “MiTM” feature

Now at least in Firefox it shows as the Letsencrypt cert - and the Chrome cache I guess needs to clear to show there

Kaspersky it seems is a free antivirus PITA


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