[CentOS] [CentOS-announce] CVE-2014-0160 CentOS 6 openssl heartbleed workaround

Wed Apr 9 15:37:39 UTC 2014
Johnny Hughes <johnny at centos.org>

On 04/09/2014 09:27 AM, Johnny Hughes wrote:
> On 04/09/2014 09:09 AM, Markus Falb wrote:
>> On 09.Apr.2014, at 15:54, Johnny Hughes <johnny at centos.org> wrote:
>>
>>> On 04/07/2014 08:30 PM, Always Learning wrote:
>>>> Thank you.
>>>>
>>>> What will the temporary packages be called ?
>>>>
>>>>
>>> Since this is the first post about the openssl update, I want to answer
>>> a couple questions here:
>>>
>>> 1.  The first susceptible version of openssl in a CentOS release was
>>> openssl-1.0.1e-15.el6, released on December 1, 2013.
>>>
>>> 2.  The version of openssl that you should install to fix the issue is
>>> openssl-1.0.1e-16.el6_5.7, released on April 8, 2014.
>>>
>>> 3.  Versions of CentOS-6.5 openssl that were affected are: 
>>> openssl-1.0.1e-15.el6, openssl-1.0.1e-16.el6_5,
>>> openssl-1.0.1e-16.el6_5.1, openssl-1.0.1e-16.el6_5.4.
>>>
>>> 4.  Only CentOS-6.5 was affected.  CentOS-6 at versions 6.4 or earlier
>>> was not affected.  No versions of CentOS-5 (or any other CentOS) were
>>> affected.
>>>
>>> Besides doing updates, things you should do include:
>>>
>>> 1.  Besides doing the updates, you should replace any certificates using
>>> SSL or TLS that are openssl based.  This includes VPN, HTTPD, etc.  See
>>> http://heartbleed.com/ for more info on impacted keys.
>> update openssl, reissue the certificates (with new key!), revoke the old certificates.
>> So far so good, but it goes further, doesn't it? Not only the ssl key could have been 
>> leaked, but also other sensible data. session keys, passwords, ... to handle this bug 
>> consequently, not only the ssl key and certificate has to be replaced, but also
>> passwords, etc., i.e. every piece of sensible data that could have been transported
>> over tls encrypted connections. Am I correct?
> If someone actually got a copy of your old private-key and if they also
> had the ability to log all the traffic to and from your site, they could
> decrypt that.  Not likely to have happened.  They could also use that 
> old private key to act as if they are your site until that certificate
> is revoked.
>
> If someone actually used the exploit against your server before you
> installed the update, they can see the things in memory (in random
> chunks) ... so they could see a username and password or other data that
> might be in memory at that time.  The ultra safe thing would be to
> assume all your passwords for SSL/TLS things are compromised.
>
>> This was about server side certificates, and that's a controlled environment. After
>> you fixed your server it is not vulnerable anymore. Another issue is client certificates,
>> and I am quite unsure the implications on these.
> It is only things that actually used SSL in memory (like httpd, imaps,
> pop3s, etc) . those certificates COULD have been impacted.
>
> openssh was not impacted (based on my reading).
>> I am assuming that client certificates are handed out to staff. Basically you can't
>> really control where people install client certificates and which client software is used.
>> If one is tricked to do a SSL Handshake with a malicious server, the key of the client
>> certificate is leaked. Reissue of the cert won't help because on the other day there
>> would be another malicious handshake with another bad server...
>>
>> Does this bug render authentication with client certificates obsolete/insecure/useless ?
>>
>> How does you handle client certificates after this heartbleed thing?
>> Your opinions and knowlegde or specific links about client certificates and heartbleed would be appreciated.
>>
>  If you change a private key with any of those things on the server,
> then the public (client) keys that access them would also need to be
> changed as well.  (The old ones would not work anyway).  If someone (bad
> guy who stole your private key) set up a server with the old key, the
> old clients would work with those (so that is why you need to change AND
> revoke your cert, not just change it on your machine :D)

This is an excellent write up:

http://www.theregister.co.uk/2014/04/09/heartbleed_vuln_analysis

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