D&C GLug - Home Page

[ Date Index ] [ Thread Index ] [ <= Previous by date / thread ] [ Next by date / thread => ]

Re: [LUG] OpenSSL 1.0.1 "Heartbleed" vulnerability

 

On Tue, Apr 08, 2014 at 02:27:42PM +0100, bad apple wrote:
> And you know what? I'm not that worried actually. Whilst it is obviously
> a catastrophic flaw in OpenSSL I've been using PFS (Perfect Forward
> Security) everywhere, with no exceptions, for a while now after the
> CRIME/BEAST attacks and this heavily mitigates the impact. This renders
> any recorded traffic flows useless even with a compromised cert and
> forces an attacker back to  computationally expensive active MITM
> attacks - definitely possible, but back to manageable levels of worry,
> not "the sky is falling" levels.

Obviously, PFS is a particularly good idea, but isn't that only
necessary against powerful adversaries? This vulnerability means that
anyone can potentially steal any information stored in memory on your
server running OpenSSL.

> Obviously, the researchers want to talk up their finding as much as
> possible but I want to see a PoC of this 'easy' recovery of openssh
> certs/keys, user+pass details, etc, and I'm not the only one. I don't
> think it follows that it's anywhere near as easy as they're stating that
> it is - I mean, *any* data? From a vulnerability that can 'only' read up
> to 64k in the process that does the TLS heartbeat without a choosable
> offset and a rapidly growing heap? Sure, this is bad, but is it that
> bad? I want to see code.

Yahoo login details?

http://blog.fox-it.com/2014/04/08/openssl-heartbleed-bug-live-blog/

(Ah, you've found that blog post too.)
 
> I had a good look at the various honeypots we run during the chaos which
> quite intentionally obviously catch a lot of bad behaviour and run
> intentionally weak security - if this was really as bad as the
> researchers were saying then I would expect to see them utterly
> compromised at this point yet none of the planted canaries have been
> triggered at all other than the usual boring daily crap. I'd expect them
> all fully and comprehensively root compromised with most of the usual
> logging conspicuously absent yet despite their routine daily torrent of
> abuse they're just functioning as usual.

I don't think the flaw has been widely known for long enough for attacks
to have been automated. And there are many millions of vulnerable
servers. So I think it's normal that a few honeypots haven't been
compromised. And it might take a while. And perhaps they've only
obtained the private keys and haven't done anything to them.

> This again makes me think that
> while it's entirely possible, if not probable, that our friends at the
> NSA/GCHQ/etc are entirely skilful enough to have detected and started
> exploiting this bug it's either not as bad as stated, harder to reliably
> exploit than stated (you're going to notice in the logs when your SSL
> linked services start crashing a lot), less well spread than expected,
> or all of the above.
 
I don't think anyone has suggested that attacks are widespread. 

> There are already several online tools to scan a site for vulnerability:
> 
> http://filippo.io/Heartbleed/

This one gives false positives.

> http://s3.jspenguin.org/ssltest.py

Doesn't work for me. (Gives empty file.)
 
> One of my friends emailed earlier from the depths of his server room:
> "Thank god I don't run Linux on any of my machines any more: I'm so glad
> I switched them all to Windows XP today!"

:-)

Anyway, sorry to hear about your lack of sleep over this. Just think of
all those people at the three/four letter agencies who have spent the
night reading as much server data as possible.

Martijn.


-- 
The Mailing List for the Devon & Cornwall LUG
http://mailman.dclug.org.uk/listinfo/list
FAQ: http://www.dcglug.org.uk/listfaq