HTTP/3 is the third major version of the Hypertext Transfer Protocol where it uses the QUIC protocol.

As of now, the Worry-Free Business Security agent does not fully support HTTP/3 scanning with both Web Reputation Services and URL Filtering. The following workarounds are recommended to still use the mentioned functionalities:

Option 1: Block UDP, ports 80 and 443 via Firewall

This option would automatically shift browser to use HTTP2/1.1 automatically. Please refer to instructions from your firewall vendor.

• Fortinet article on Google Chrome/QUIC
• Sophos article on QUIC protocol and Sophos Firewall

Option 2: Disable Browser HTTP/3 support

• Microsoft Edge
  1. Start Microsoft Edge.
  2. In the Address Bar, type in "edge://flags/#enable-quic".
  3. Switch the option to disabled.

  

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• Google Chrome
  1. Start Google Chrome.
  2. In the Address Bar, type in "chrome://flags/#enable-quic".
  3. Switch the option to disabled.

  

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• Mozilla Firefox
  1. Start Mozilla Firefox.
  2. In the Address Bar, type "about:config".
  3. Search "network.http.http3.enable".
  4. Shift setting to "false".

  

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• As an alternative, you can download and use these scripts to automate the modifications.
• Customers can use Geekflare to confirm if the website has adapted HTTP/3.

For support assistance, please contact Trend Micro Technical Support.