Internet Explorer refuses to connect to sites with untrusted SSL certificates

internet explorerSecurityssl

IE has started exhibiting a strange behavior. We have several intranet nodes (routers) that are configured to use HTTPS for access, but which have untrusted / self signed certificates on them. At some unidentifiable point in the recent past, there was no problem connecting to these devices. That is no longer true. When you attempt to connect, and choose option 3 ("to connect to the site anyways") IE comes back immediately with a "Connection Unavailable" screen. This occurs in IE8 and now (ugh) ie9.

Firefox has no problem connecting to these locations, which indicates that its not a TCP stack problem. Google Chrome fails to connect; but then Google Chrome fails at a lot of stuff.

We have tried adding them as trusted sites. No difference.

Clearly there is some obscure setting or MS has come out with a patch that breaks things. Any ideas?

Best Answer

This problem is caused by a very recent ms update: kb2585542

There is a fixit associated with ms12-006 which allows you to turn off part of the update. Issues are described at http://support.microsoft.com/kb/2643584

Specifically Microsoft Fix it 50824 needs to be applied. You then need to update ie to only use ssl3 and tls1.2 and for our systems this fixed the problem