Archived: Adding Security Exception in Firefox 35

PKI Tutorials - Herong's Tutorial Examples

∟Archived: Adding Security Exception in Firefox 35

This section provides a tutorial example on how to add a security exception in Mozilla Firefox to continue visiting an HTTPS Website with an un-trusted certificate.

What should you do when Mozilla Firefox tells you that "Your connection is not secure"? My suggestions is:

Check the Website address to make sure you are not on a phishing site. For example, instead of yahoo.com you entered yah00.com, which could be a phishing site to steal your private data.
Ask Mozilla Firefox to add an exception to let you continue to use this site.
Or ask Firefox to show the certificate received from the site, review the certificate and fix the problem.

Here is what I did to add a security exception to pass the error page:

1. Open Mozilla Firefox to visit to https://login.yahoo.com again and wait for the error page.

2. Click the link "I Understand the Risks". Mozilla Firefox displays more warning messages:

If you understand what's going on, you can tell Firefox to start
trusting this site's identification. Even if you trust the site,
this error could mean that someone is tampering with your connection.

Don't add an exception unless you know there's good reason why this
site doesn't use trusted identification.

[ Add Exception... ]

3. Click the "Add Exception" button. The "Add Security Exception" dialog box shows up:

Add Security Exception - Mozilla Firefox — Adding Security Exception in Mozilla Firefox

4. Read messages on the dialog box carefully:

You are about to override how Firefox identifies this site.
Legitimate banks, stores, and other public sites will not ask
to do this.

Server Location: https://login.yahoo.com/...

Certificate Status - This site attempts to identify itself with
invalid information.

Unknown Identity - Certificate is not trusted, because it hasn't
been verified by a recognized authority.

[ ] Permanently store this exception

5. Click the "Confirm Security Exception" button. The Yahoo login page shows up.

I could continue to login to my Yahoo account and access my email box if I want to, because I can trust the Yahoo site.

Note that I left the "Permanently store this exception" checkbox unchecked, because I don't want Firefox to remember this exception. When I close Firefox and open it to visit https://login.yahoo.com, I want to see the error page again.