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firefox VPN This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely

  • 3 replies
  • 1 has this problem
  • 6 views
  • Last reply by cor-el

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I installed firefox latest on windows 10 and it works perfectly fine.

but as soon as I connect to my corporate network via Cisco VPN. Firefox stops working and all websites get this error

Your connection is not secure

The owner of www.youtube.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.

This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate.

Learn more…

Report errors like this to help Mozilla identify and block malicious sites

If I log out of my corporate VPN it again starts to work.

This question has been asked before and the solution was

1. about:config 2. root 3. security.enterprise_roots.enabled = true

I have already done that and rebooted my machine after doing it. still the problem occurs when I sign in into the corporate VPN.

Yes I hate IE and Chrome so please help me fix this.

I installed firefox latest on windows 10 and it works perfectly fine. but as soon as I connect to my corporate network via Cisco VPN. Firefox stops working and all websites get this error Your connection is not secure The owner of www.youtube.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may only connect to it securely. As a result, it is not possible to add an exception for this certificate. Learn more… Report errors like this to help Mozilla identify and block malicious sites If I log out of my corporate VPN it again starts to work. This question has been asked before and the solution was 1. about:config 2. root 3. security.enterprise_roots.enabled = true I have already done that and rebooted my machine after doing it. still the problem occurs when I sign in into the corporate VPN. Yes I hate IE and Chrome so please help me fix this.

All Replies (3)

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That sounds more like it some policy enforcement on the VPN site not a FF Browser caused issue. Since you said it works when the VPN is turned off. They most likely monitor and permit only certain site access through their VPN. So this isn't a FF help issue but your VPN restricted usage through them.

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So when I use Chrome, IE and Edge i can browse youtube.com before and after connecting to VPN.

When I use firefox. I can browse youtube.com before connecting to VPN but not after it.

If the firewall was blocking the site youtube.com, then all browser should not be able to go to the website right? why is it that the browse fails only for firefox?

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

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

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

  • open the Servers 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.