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Intermediate CA not trusted by Firefox

  • 3 replies
  • 4 have this problem
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  • Last reply by sengarth

sengarth
sengarth
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I have a certificate issued by Sectigo recently and have successfully installed on my web server. My users are able to access it via Chrome, Internet Explorer and Safari with no issues.

However everyone experiences the "Your connection is not secure" warning message.

After some investigation, it seems that the intermediate CA issued by Sectigo is not included in Firefox's certificate store and hence the chain of trust could not be established.

What I want to ask is, the intermediate CA is already listed in Mozilla's CCADB (https://ccadb-public.secure.force.com/mozilla/PublicAllIntermediateCerts).

Why is it that error still appears on Firefox? It does not help even when security.enterprise_roots.enabled is set to true.

The only workaround so far is to manually import the intermediate CA via Privacy & Security -> Certificates, however this should not be performed in the first place if the isssuer CA is already trusted and works fine with all other browsers.

I have a certificate issued by Sectigo recently and have successfully installed on my web server. My users are able to access it via Chrome, Internet Explorer and Safari with no issues. However everyone experiences the "Your connection is not secure" warning message. After some investigation, it seems that the intermediate CA issued by Sectigo is not included in Firefox's certificate store and hence the chain of trust could not be established. What I want to ask is, the intermediate CA is already listed in Mozilla's CCADB (https://ccadb-public.secure.force.com/mozilla/PublicAllIntermediateCerts). Why is it that error still appears on Firefox? It does not help even when security.enterprise_roots.enabled is set to true. The only workaround so far is to manually import the intermediate CA via Privacy & Security -> Certificates, however this should not be performed in the first place if the isssuer CA is already trusted and works fine with all other browsers.

Chosen solution

Firefox only includes root certificates. Intermediate certificates have never been included in Firefox. Web servers need to send to send a full certificate chain that includes all required intermediate certificates. Firefox stores intermediate certificates send by a website that can be used in future visits to websites that do not send a full certificate chain.

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All Replies (3)

hellosct1
hellosct1
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hi,

First you have to check the settings of your antivirus, especially if you use AVG or Avast

After, I share a link that brings many solutions

http://mzl.la/1M2JxD0

thank's

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
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Chosen Solution

Firefox only includes root certificates. Intermediate certificates have never been included in Firefox. Web servers need to send to send a full certificate chain that includes all required intermediate certificates. Firefox stores intermediate certificates send by a website that can be used in future visits to websites that do not send a full certificate chain.

sengarth
sengarth Question owner
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Answered my question, appears now there are only 2 scenarios that could resolve the warning message in Firefox without requiring client-user's manual intervention.

Scenario 1. Configure the web server to send the intermediate CA to the client with Firefox browser

Scenario 2. Client happen to visit another website that sends the same intermediate CA and it is cached in Firefox's certificate store, future sites that do not send such CA do not have to send to the client.