I get an error too with Firefox 30.0 and Firefox 33.1.1 on Windows 7, but not with Firefox ESR 31.2.0 on RHEL 5, nor with IE 11 on Win7. With FF 30.0, it didn't even give me a chance to look at the cert or add an exception, but after updating to 33.1.1 I could. It's an Entrust, Inc. certificate, which doesn't seem like a no-name CA to me, particularly since many browsers accept it without complaint. Maybe some Windows builds of Firefox are missing some root CAs or have a bug that prevent them from parsing all of the root CAs correctly? Doesn't look like a MitM attack in any case.

On 11/21/2014 12:24 AM, Hartmut W Sager wrote:

I just tested it, and I also get the "untrusted" treatment, using Windows Vista and Firefox 33.1.1 (which is a Firefox upgrade I just got in the last 2-3 days).

Hartmut W Sager - Tel +1-204-339-8331

On 21 November 2014 00:14, Trevor Cordes <trevor@tecnopolis.ca> wrote:

Does anyone else get a cert error on this site:

https://taxcess.gov.mb.ca/

It's invalid in Firefox (latest F19 version: 33.1, just came out today)
on Linux. But it works ok on Chrome in Windows. Chrome shows the cert
is brand new this month (I had never had a problem with their site
before).

Weird that a trust-validated site like that would have cert problems,
unless they chose a no-name CA?

Unless someone is MitM'ing me...

-- 
Gilles R. Detillieux              E-mail: <grdetil@scrc.umanitoba.ca>
Spinal Cord Research Centre       WWW:    http://www.scrc.umanitoba.ca/
Dept. of Physiology and Pathophysiology, Faculty of Health Sciences,
Univ. of Manitoba  Winnipeg, MB  R3E 0J9  (Canada)