What do the SSLv3 error messages mean on Firefox?

Firefox versions 33 and lower: This article applies to newer versions of Firefox. If you are unable to use a newer version, install this official Mozilla add-on to disable SSLv3 immediately.

Starting with Firefox version 34, Firefox blocks Secure Sockets Layer version 3.0 (SSLv3) to protect your information from attacks. SSLv3 is a type of technology that some websites use to connect to a server. It is no longer secure, which makes it easy for hackers to extract your personal information during a connection. For more information, see this blog post.

What happens when you access vulnerable sites

When you try to access a site that only supports Secure Sockets Layer version 3.0 (SSLv3), Firefox blocks it and displays a message, Unable to Connect Securely, explaining that Firefox cannot guarantee the safety of your data on that website because it uses SSLv3, a broken security protocol.


If you see this message, please contact the website owner to let them know about the problem.

Additional precautions

To further protect yourself from attacks, keep Firefox up to date. The simplest way to do this is to set up automatic updates:

  1. Click on the menu button new fx menu , then click OptionsPreferences.
  2. Click the Advanced panel, then click the Update tab, and make sure that Automatically install updates is checked.

If you use your Linux distribution's packaged version of Firefox, there will be no Update tab in the panel. Instead, Firefox updates are managed by the Update Manager for your distribution, and any updates should be installed automatically.

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