Firefox "certificate" question

Factual Questions
1

Recently, whenever I try to sign into my comcast email account I get a popup that says some kind of “certificate” has expired from “oasc02.247realmedia.com.” It asks me if I want to continue or cancel. What does this mean? It only happens in firefox. How can I get this thing to stop popping up?

2

Hi. The certificate in question is used to prove to your browser that the site is indeed who it claims to be. The certificate stores the name of the site, when the “certification” starts and ends and who issued the certificate. Normally, a site will renew their certificate before it expires to stop you getting the message you see.

If you believe the site is who it claims to be - e.g. you have clicked a link from a site you trust, it’s generally harmless to accept the cert even though the date has expired. Cases where you might not want to do this is where the cert is used to prove a site follows a security policy adminstered by the certificate issuer - if the cert has expired then maybe they didn’t pass the audit requirements any longer?

You mention you see this in firefox only, which I take to mean you don’t get the same problem in Internet Explorer - it’s likely that the root certificate bundle for Firefox (e.g. the certificate for the site which issued the realmedia certificate) has expired or is not included in the IE certificates.

I’ve had a quick google for “firefox root certificate update” but nothing very interesting turned up.

There is a good (but technical) explanation of how SSL certs work here:
http://docs.sun.com/source/816-6156-10/contents.htm

In short, if you accept the certificate your communication will be encrypted and probably as secure as normal. There may be an option to not warn about this cert again - I don’t know as I mainly use IE. Alternatively, email the site admin (www@site.com) and let them know - they may have forgotten to renew!

cheers,
Tim

3

Thanks for the info and the link, Tim. I think it’s probably harmless. The site is just my Comcast mailbox. I appreciate the response. It’s helped remove any minor anxiety I had about it.