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Firefox says that all websites have an invalid security certificate.. All my other browsers work fine! I tried disabling all addons and resetting connection

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  • 1 has this problem
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  • Last reply by cadao

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Firefox says that all websites have an invalid security certificate.. All my other browsers work fine! I tried disabling all addons and resetting connection, but nothing has worked.I can't even connect to mozilla support!

Firefox says that all websites have an invalid security certificate.. All my other browsers work fine! I tried disabling all addons and resetting connection, but nothing has worked.I can't even connect to mozilla support!

Chosen solution

Yes, the issuer of the certificate is your security software.

Subject 	C=US, ST=California, L=Mountain View, O=Mozilla Foundation, OU=WebOps, CN=support.mozilla.org
Issuer 	OU=generated by Avast Antivirus for SSL/TLS scanning, O=Avast Web/Mail Shield, CN=Avast Web/Mail Shield Root

See this article about Avast.

Read this answer in context 👍 1

All Replies (6)

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You can check if there is more detail available about the issuer of the certificate.

  • click the "Advanced" button show more detail
  • click the blue SEC_ERROR_UNKNOWN_ISSUER message to show the certificate chain
  • click "Copy text to clipboard" and paste the base64 certificate chain text in a reply

If clicking the SEC_ERROR_UNKNOWN_ISSUER text doesn't provide the certificate chain then try these steps to inspect the certificate.

  • open the Server tab in the Certificate Manager
    • Options/Preferences -> Privacy & Security -> Certificates: View Certificates -> Servers: "Add Exception"
  • paste the URL of the website (https://xxx.xxx) in it's Location field.

Let Firefox retrieve the certificate -> "Get Certificate"

  • click the "View" button and inspect the certificate

You can see detail like the issuer of the certificate and intermediate certificates in the Details tab.

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cor-el said

You can check if there is more detail available about the issuer of the certificate.
  • click the "Advanced" button show more detail
  • click the blue SEC_ERROR_UNKNOWN_ISSUER message to show the certificate chain
  • click "Copy text to clipboard" and paste the base64 certificate chain text in a reply
If clicking the SEC_ERROR_UNKNOWN_ISSUER text doesn't provide the certificate chain then try these steps to inspect the certificate.
  • open the Server tab in the Certificate Manager
    • Options/Preferences -> Privacy & Security -> Certificates: View Certificates -> Servers: "Add Exception"
  • paste the URL of the website (https://xxx.xxx) in it's Location field.
Let Firefox retrieve the certificate -> "Get Certificate"
  • click the "View" button and inspect the certificate
You can see detail like the issuer of the certificate and intermediate certificates in the Details tab.

Ok, here is the info:

https://support.mozilla.org/1/firefox/59.0.3/WINNT/en-US/security-error Peer’s Certificate issuer is not recognized. HTTP Strict Transport Security: false HTTP Public Key Pinning: false Certificate chain: -----BEGIN CERTIFICATE----- MIIESTCCAzGgAwIBAgIQWvc8MiykIUKvH8S/AsI/0zANBgkqhkiG9w0BAQsFADCB gTE6MDgGA1UECwwxZ2VuZXJhdGVkIGJ5IEF2YXN0IEFudGl2aXJ1cyBmb3IgU1NM L1RMUyBzY2FubmluZzEeMBwGA1UECgwVQXZhc3QgV2ViL01haWwgU2hpZWxkMSMw IQYDVQQDDBpBdmFzdCBXZWIvTWFpbCBTaGllbGQgUm9vdDAeFw0xNzA5MjAwMDAw MDBaFw0xODEwMzExMjAwMDBaMIGGMQswCQYDVQQGEwJVUzETMBEGA1UECBMKQ2Fs aWZvcm5pYTEWMBQGA1UEBxMNTW91bnRhaW4gVmlldzEbMBkGA1UEChMSTW96aWxs YSBGb3VuZGF0aW9uMQ8wDQYDVQQLEwZXZWJPcHMxHDAaBgNVBAMTE3N1cHBvcnQu bW96aWxsYS5vcmcwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQC6Pc/5 Ym92iVxZe7zLOR7IB9wjZXc2oryl0KLp19QBajDP7r3X+UZlXP1ZC3h4N3CRKe6G OV4hqFmJe88FScwcKNGh1z42gXgsigOy87UDxAYRrvpjIinJz7oITeVZoIsf2UIm xdZ7dJyjhFi4rBj5WHNvtZPTwXvbpoax5/WGzAh1L6tOF1zABH3St5iHH+7XAiYI fC1SaR1fALUP+LUMROpkm9YImU40XO5f/zGtvFJjNtw11Y25ANN/m9GfLQu8hSN0 sW7ctT7P/NNyFQVb2Jme68axpP1eVEVSUD/EFx21sX8GOfiSCR5ibXTa+Rkh2NnV qEx1b3iA8KgXtbbNAgMBAAGjgbUwgbIwHwYDVR0jBBgwFoAUsjA21ZrvD+N4fN79 82thAsDscvwwHQYDVR0OBBYEFKNcAPirCasC5wR4TwpVz9cQH1ReMDMGA1UdEQQs MCqCE3N1cHBvcnQubW96aWxsYS5vcmeCE3N1cHBvcnQubW96aWxsYS5jb20wDgYD VR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjAMBgNV HRMBAf8EAjAAMA0GCSqGSIb3DQEBCwUAA4IBAQCqAELV4JZ89KUbuMSgT5ESWyZB ma+bPgPmgK9j+6vzK7ftA7OfgTsHisyzkDR0BCjJKtqScD2Ibu+ozpnpEXqaqvTi UviCz0vBJtKfKV0jBOpobqnfnph7Fu6JR8P2+wdU5RaBpP5s/d+52uhSO8Cg3YCk YC9IFogQvQVC9Ak6u33zoBF9xbUuU39H1ikc9HW/2cLaP2h15q0WCXczgacr7dH5 GQyTRTSX5Pf3i7+qNqpBX8aNQLe2BM7G1Z8HE3vyv5QzaDrULb53vbkbqiZ56+0D 0db4RCUNf2zjaTZxrCo4HOJx0eHzyuD4dzL7dJQ3hxpBW3P1hHfEdvcRABIg -----END CERTIFICATE----- -----BEGIN CERTIFICATE----- MIIEAzCCAuugAwIBAgIQai7m5TjgPUy0wRLuipZiRzANBgkqhkiG9w0BAQsFADCB gTE6MDgGA1UECwwxZ2VuZXJhdGVkIGJ5IEF2YXN0IEFudGl2aXJ1cyBmb3IgU1NM L1RMUyBzY2FubmluZzEeMBwGA1UECgwVQXZhc3QgV2ViL01haWwgU2hpZWxkMSMw IQYDVQQDDBpBdmFzdCBXZWIvTWFpbCBTaGllbGQgUm9vdDAeFw0xMDAxMDExMjAw MDBaFw00MDAxMDExMjAwMDBaMIGBMTowOAYDVQQLDDFnZW5lcmF0ZWQgYnkgQXZh c3QgQW50aXZpcnVzIGZvciBTU0wvVExTIHNjYW5uaW5nMR4wHAYDVQQKDBVBdmFz dCBXZWIvTWFpbCBTaGllbGQxIzAhBgNVBAMMGkF2YXN0IFdlYi9NYWlsIFNoaWVs ZCBSb290MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAu/9u2c1QaV4H DfaOeYmtio9gsIG1vH0KQLLRJIKEhMIO21+KzVNLadU0ksB9WqX0UdmxghgI1BUK gvHzbDh7X6jmRcUzU1pM5iifY20twF8bgRuvuuQCcsYoFFo4J/PVT5W87ilK8a9D h//YFZ28k9MpLWni/++oQa5M+MaXCc1lKZ4ZpJNvl5fJyIftF5Mtv8vNc1Dx8JfZ WsnOzmwcOIlWJpj3FTT+gQqgSh7W+CsEapPOCKOedKVVUYXXwuwykSrIGzRd8Qmh E0ouGZdsi51S3DnVG7NX+34xWvVjtpo6IzG2TDTA9e9i5AmUIjBC9T0qdLAEBiWF kWMfciSCKQIDAQABo3UwczAPBgNVHRMECDAGAQH/AgEAMAsGA1UdDwQEAwICBDAT BgNVHSUEDDAKBggrBgEFBQcDATAdBgNVHQ4EFgQUsjA21ZrvD+N4fN7982thAsDs cvwwHwYDVR0jBBgwFoAUsjA21ZrvD+N4fN7982thAsDscvwwDQYJKoZIhvcNAQEL BQADggEBAI7N5ptR6zHHytYbmRcTcxVP3lwAQE5BMQ+aEanOBUP6RAQLnEGudZiY 5ch8E2jENqahvN9Y1XRFXRdS7JC8RLM0DZGj2h2SXrIcXK/HRMInPdoqoxdviULk uRPeAuDYM+M4UTzD+dWhdtf0sIHig4uezL+Hm2T15uz+Xd0zG0dY9ADDzAT48xDN YsscpjabtyFGOQQ4nC4yiqGWjoAGC+sDlZCxlN5ZJ6uMCYV7Yrhq4yl7XBjczYeo PgYEKrbvIMBcCmmg7wqm6oWjwqYLb0OSir//ZaYwb91evQQUnxf3Baz9zxvnJ7Vs BN3Ue1uN2Lvm7Io4D+JBPCPxfoCgiQs= -----END CERTIFICATE-----

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I found this from where you said also-this leads me to believe it might be something to do with my Antivirus (Avast):

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Chosen Solution

Yes, the issuer of the certificate is your security software.

Subject 	C=US, ST=California, L=Mountain View, O=Mozilla Foundation, OU=WebOps, CN=support.mozilla.org
Issuer 	OU=generated by Avast Antivirus for SSL/TLS scanning, O=Avast Web/Mail Shield, CN=Avast Web/Mail Shield Root

See this article about Avast.

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cor-el said

Yes, the issuer of the certificate is your security software. Subject C=US, ST=California, L=Mountain View, O=Mozilla Foundation, OU=WebOps, CN=support.mozilla.org Issuer OU=generated by Avast Antivirus for SSL/TLS scanning, O=Avast Web/Mail Shield, CN=Avast Web/Mail Shield Root See this article about Avast.

Thanks so much! I fixed it. This is what I did with Avast:

Open the dashboard of your Avast application. Go to Settings > Active Protection and click Customize next to Web Shield. Uncheck the Enable HTTPS Scanning setting and confirm this by clicking OK.