RE: SEC webpages inaccessible due to Firefox blocking servers with weak DH ciphers

[Matthew Huff <mhuff () ox com>]

After making the about:config changes, no warning is given to the user about the bad ciphers. Even if you click the SSL 
lock icon, no warning is given. Only if you know that the connection being made with "TLS_RSA_WITH_AES_128_CBC_SHA,128 
bit keys, TLS 1.0" is a bad thing would you have any clue.






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-----Original Message-----
From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Robert Drake
Sent: Friday, July 17, 2015 8:42 AM
To: nanog () nanog org
Subject: Re: SEC webpages inaccessible due to Firefox blocking servers with weak DH ciphers



On 7/17/2015 4:26 AM, Alexander Maassen wrote:
> Well, this block also affects people who have old management hardware
> around using such ciphers that are for example no longer supported. In my
> case for example the old Dell DRAC's. And it seems there is no way to
> disable this block.
>
> Ok, it is good to think about security, but not giving you any chance to
> make exceptions is simply forcing users to use another browser in order to
> manage those devices, or to keep an old machine around that not gets
> updated.
Or just fallback to no SSL in some cases :(  We have some old vendor 
things that were chugging along until everyone upgraded firefox and then 
suddenly they stopped working.  The "fix" was to use the alternate 
non-SSL web port rather than upgrade because even though the software is 
old, it's too critical to upgrade it in-line.

The long term fix is to get new hardware and run it all in virtual 
machines with new software on top, but that may be in next years 
budget.  I've also got a jetty server (opennms) that broke due to this, 
so I upgraded and fixed the SSL options and it's still broken in some 
way that won't log errors.  I have no time to track that down so the 
workaround is to use the unencrypted version until I can figure it out.

Having said that, it seems that there is a workaround in Firefox if 
people need it.  about:config and re-enabling the weak ciphers. 
Hopefully turning them on leaves you with a even bigger warning than 
normal saying it's a bad cert, but you could get back in.  This doesn't 
help my coworkers.  I'm not going to advise a bunch of people with 
varying levels of technical competency to turn on weak ciphers, but it 
does help with a situation like yours where you absolutely can't update 
old DRAC stuff.

https://support.mozilla.org/en-US/questions/1042061