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Fixing the “Port Restricted for Security Reasons” error in Firefox

Port Restricted for Security Reasons
This address uses a network port which is normally used for purposes other than Web browsing. Firefox has canceled the request for your protection.

This is an error I met for the first time earlier today in Firefox. I thought wow, they’re really starting to pick noob-friendly default settings now. But well, as usual they provide us with a way to customize the browser to our need: the responsible settings for this are network.security.ports.banned and network.security.ports.banned.override.

network.security.ports.banned contains a list of ports that will be added to the default (hard-coded) banned list. If the port you wanted to reach is in this variable, remove it (restarting the browser may be necessary for the setting to apply). Ports are listed separated by commas.
network.security.ports.banned.override contains a list of ports that will be removed from the default (hard-coded) banned list. If the port you wanted to reach is not in network.security.ports.banned, you’ll need to add it here.

To finish my story, the port I wanted to access (8118) was added to the banned list most likely by the TorButton extension.

More details:
network.security.ports.banned on MozillaZine
network.security.ports.banned.override on MozillaZine
Mozilla Port Blocking

Posted in Firefox.


2 Responses

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  1. Kin says

    I have this error but neither of those keys are present in my about:config

    This is an outrage for Mozilla to be steering me away from content and wasting my time like this.

    • David Dernoncourt says

      Actually, Namoroka doesn’t seem to have this setting anymore. And I didn’t take note of what URL was causing me this trouble, so I can’t tell if I’m still having it…

      Edit: just checked TFM ^^, and rediscovered that network.security.ports.banned.override doesn’t exist by default, you need to create it from about:config.



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