It occurs appears when I try to use a SSL client certificate with Safari. Of course, authentication is broken as it just fails on an 403 error page.
So it seems that Safari is the last browser which was not patched against CVE-2009-3555 !
2009 !! At least, I quickly checked the other browsers I had around and they were fine: IE, Firefox, Chrome… I am having an issue with Opera also, but although I have not identified the problem yet, it seems unrelated (and does not throw the same error).
Note that I reported the issue to Apple, but I did not receive any answer. Silence on the wire.
Check the official doc for more details. With this option activated, you can now safely upgrade openSSL and mod_ssl without breaking your clients. They should have done it from the begining, shouldn’t they ?
The next step will be to move on to the new protocol definitely, to solve for good the CVE-2009-3555 vulnerability. For that we have to wait for the browsers to support it.
Firefox has started to work seriously on it and we can expect some support in the next releases (some settings will be possible through about:config).
They even created a test site. This screenshot was taken from Google Chrome (5.0.366.2, openSUSE repo) which already has support for the SSL protocol :