Re: [Full-disclosure] Getting Off the Patch

["Cor Rosielle" <cor@xxxxxxxxxxxxx>]

I don't agree with the statement: "From a security standpoint, patching is
better than not patching.  Period.".

Sometimes patching is the right solution, often it is not. Since some asked
experiences from larger companies, here is one:

In 2001 I was responsible for maintaining all kinds of systems and services
at a telephony and internet provider. One morning a list with our company
name in it was mentioned in the radio news bulletins. We also found our name
in this list in articles in newspapers. A "hacker" found we didn't install a
patch on one of our web servers which ran IIS 5.0 on Windows 2000. The patch
was available for about 3 months and the hacker claimed he could attack our
server because of this specific patch missing. Because of his "ethical
standards" he did not try to really attack the server but just publish about
the shameful patching policies in large companies.  
Three years later, when a new website was developed, the server was
replaced. The patch was still not installed. Even though we were in the
radio news bulletins and news papers and the world knew about our vulnerable
server, no successful attack occurred in all that time. 

O yes, they tried. I've seen it in our log files. But because other defense
mechanisms, the known exploit did not work on our server. And since the web
server was in no danger without this patch, we decided installing the patch
would be a higher risk than leaving the server as is. 

I did not know about the OSSTMM in those days. If I did, I could have
explained why patching is not always the best solution: it interferes with
your operations. And if it influences you operations, you better control it.
Not blindly execute it and install the patch using an automated update
process, but actually control it. 
So the first thing to do is to decide if applying a patch is useful at all.
And often it is not! E.g. why would you even consider to install MS10-085 on
a http-only web server (MS10-085 apparently fixes an error in TLS
handshake)? (Don't flame me on this one, it's just meant as an example). And
if you concluded a patch is useful, then you decide if you do need to
install it, or if it is not really necessary to install it. And if you
install it, then decide if you do it manually, in a controlled manner, or
use an automated update process, in an uncontrolled manner. The OSSTMM helps
you to realize that an automated update process increases the attack
surface, which better be controlled.
Another option of course is to blindly install it, because you trust your
vendor (you know, the one that provided buggy software in the first place).
Then your not controlling, but trusting. Read chapter 5 in the OSSTMM to
find out if that is wise for this particular vendor, or not.

Bottom line is that patching interferes operations and therefore, from a
security standpoint, it either has to be controlled or trusted. It is not
always true that patching is better than not patching. So I would slightly
like to rephrase that statement:
"From a security standpoint, thinking is better than not thinking.
Period.". (Now would it surprise you if I told you that critical thinking is
one of the starting points of the OSSTMM??.

Cor Rosielle
Chief Technology Officer



> -----Original Message-----
> From: full-disclosure-bounces@xxxxxxxxxxxxxxxxx [mailto:full-
> disclosure-bounces@xxxxxxxxxxxxxxxxx] On Behalf Of Thor (Hammer of God)
> Sent: dinsdag 18 januari 2011 19:39
> To: Valdis.Kletnieks@xxxxxx; Cal Leeming [Simplicity Media Ltd]
> Cc: full-disclosure@xxxxxxxxxxxxxxxxx
> Subject: Re: [Full-disclosure] Getting Off the Patch
> 
> >On Mon, 17 Jan 2011 22:29:13 GMT, "Cal Leeming [Simplicity Media Ltd]"
> said:
> >
> >> Most people wouldn't rely solely on patch day to protect their
> >> systems/network
> >
> >You're in for a surprise.
> 
> One, as Cal pointed out, you cut out the context of what he said/meant.
> And two, so what if they do?  At least they are patching.   If security
> is the goal, then advocate for security in depth.  From a security
> standpoint, patching is better than not patching.  Period.  If you have
> controls in place to mitigate exposure, then they should be combined
> with patching.  Are you taking the position that the level of "being
> surprised" at the number of people who only patch dictates that they
> stop patching and try to successfully implement other controls so they
> don't have to patch?
> 
> Playing "whack a mole" was entertaining, but in all seriousness, your
> responses to this thread have been confusing to me.   Any security
> model that not only advocates non-patching, but that is designed with
> the intent of not patching is completely retarded.  I defy anyone to
> provide verifiable evidence to the contrary that is not based on a
> server and a couple of workstations.  Even the self-proclaimed
> "marketing" guy who admitted he didn't know how to patch couldn't come
> up with a single shred of substantiating research to support anything
> different.   Comparing his "research" to Einstein and general
> relativity is a level of ass-hattery that rivals some of the worst on
> the list.
> 
> So when I see you apparently supporting the idea, as someone who
> normally provides some sort of empirical backing to his statements, I
> become interested in what factors lead you to that conclusion.
> 
> t
> 
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