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:
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button
and select .
- In the panel, scroll down to Firefox Updates.
- Make sure that Automatically install updates is checked.
Firefox update settings may be absent if you use your Linux distribution's packaged version of Firefox. Instead, Firefox updates are managed by the Update Manager for your distribution and any updates should be installed automatically.
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
- Click the panel, then click the 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.
