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Re: SMS Banking

From: "Thor (Hammer of God)" <Thor () hammerofgod com>
Date: Tue, 9 Feb 2010 20:32:44 +0000
In line.


"Exactly.  So, before the incident, you would have come up with Some
Number
and said, "this is your risk."  After the incident your number would
(hopefully) change to Some Number + Some Other Number, and you could
say
"Oops.  Didn't think of that.  Sorry."

Are you trying to be clueless? [R(t)-> 0] means that the system was
inherently unreliable. That is no change before or after. I recommended
a
probability distribution that links to a financial model.


Well, if I arrive at clueless, it will definitely be because I tried.  Maybe you can teach me how to attain that 
disposition naturally.

So, ANY deployment of SQL server is inherently unreliable?  And the SMS model is also inherently unreliable. What 
system then is NOT inherently unreliable?  Might we assume that your own formula falls into this category?



" Fine.  Let's do it this way then.  We'll have someone implement an
SMS
solution for banking that we don't have anything to do with.  I'll
assess
risk my way, you assess risk with your calculator.  Since *someone* has
to
pay, are you saying that you are willing to assume responsibility for
financial losses when your numbers come out wrong?"

Yes simply I will. In case you have not as yet had a clue, I stated
reliability limits towards 0. That means the SMS solution is inherently
insecure.

"So which is it?  Is quantifying the probability of compromise "fairly
simple using a formula" or is it "not an economic function pure and
simple?""
Both.


Typical.


" Since *someone* has to pay, are you saying that you are willing to
assume
responsibility for financial losses when your numbers come out wrong?"
I am working on a hedging instrument at present, and yes, where I am
paid to
model systems I will negotiate for losses.


Excellent.  Bring your checkbook along with your math.


So where are all the lives being lost through a banking app?


They are not.  They will be when you start consulting to CIP.  Do us a favor though, test it out on your own country 
first.  But let me know before you do, my friends David and Greg are in AU.




"Surely as the most highly certified security professional in the world
you
don't need me, a mere working stiff, to find you a sponsor."
If you want me there, yes. I work by the hour, I am not going to waste
time
paying for this "opportunity". How about you come to an IEEE
conference?


So, the most highly certified security professional in the world, and the greatest global mind in computer security 
refers to an open debate where you could defend formulas that have been publically ridiculed and openly called ignorant 
as a "waste of time"?  I don't need to pay you to substantiate my claims, sir.  You just did it for free.

t




Regards,
...
Dr. Craig S Wright GSE-Malware, GSE-Compliance, LLM, & ...
Information Defense Pty Ltd



-----Original Message-----
From: Thor (Hammer of God) [mailto:Thor () hammerofgod com]
Sent: Wednesday, 10 February 2010 7:05 AM
To: craig.wright () Information-Defense com; pen-test () securityfocus com;
'full-disclosure'
Subject: RE: SMS Banking


-----Original Message-----
From: Craig S. Wright [mailto:craig.wright () Information-Defense com]
Sent: Tuesday, February 09, 2010 10:54 AM
To: Thor (Hammer of God); pen-test () securityfocus com; 'full-

disclosure'

Subject: RE: SMS Banking

First,
'Thor', get me sponsored and I will be more than happy to debate you

at

Defcon. Being in Au, it costs a little more for me to get there than

a

simple interstate flight.


Surely as the most highly certified security professional in the world
you
don't need me, a mere working stiff, to find you a sponsor.  As the
greatest
mind on the face of the globe, I'll leave that one for you to figure
out.


I am happy to be an egoist. I am not an altruist, I invest, I do not
sacrifice. So no insult.


No, we sacrifice for you.  Or will, that is, if you or your formulas
have
anything to do with real human safety.



"Your "risk formula" is ridiculous." Why? How is IT different to all
other
aspects of life and the world. Why is it sacrosanct and unable to be
modelled? As for real experience, I have been doing this over several
decades. I may be teaching at CSU (csu.edu.au - gratuitous plug), but
that
is a side line, not what I do.


Because it fails to take into account simple reality.  Risk is assessed
as
the result of human interaction, not calculated by some formula.
Information security is about people as much as it is about technology.
Your math fails here, and it fails grievously.  Have you ever been in
love
and acted out of that?  If so, then prove it mathematically.  Show me
the
variables that take into account human actions and reactions.


" What number would your formula have yielded 2 weeks before SQL
Slammer was
released?"
The same as at any time before the incident. SQL was a time degrading
function similar to the SMS example. The end result is a reliability
value
[R(t)-> 0] that approaches 0 and is prone to catastrophic failure.

The

rate
of failure being related to the no. of access paths, no. of systems

and

the
number of users.


Exactly.  So, before the incident, you would have come up with Some
Number
and said, "this is your risk."  After the incident your number would
(hopefully) change to Some Number + Some Other Number, and you could
say
"Oops.  Didn't think of that.  Sorry."




"Where is the variable for unpatched systems?"
This is a function of both local and remotely accessible services.

Some

of
these are dependant. This calculation has to account for each of

these

services on the host as well as a vulnerability model for each

service.

I am
publishing a paper on this later in the year.

"What number do we plug in for malicious employee factorization?"
A prior data from similar industries, areas etc.


So you just take historical data that may or may not have anything to
do
with anything, and apply it to your formula just because it is what has
happened before?  Your source is from only reported incidents or
discovered
incidents?  Does it take into account anything of value?  Are you
saying
that with all of your education, and your globally superior intellect,
the
only value-add you bring is to tell us what has already happened in the
past?  Seems a bit obvious if you asked me irrespective of the fact
that
it's basically worthless in the absence of an assessment.



Now, the real issue is that you (thor) seem to have this idea that
multiplying risk is a function of multiplying one made up number by
another
made up number. The 'expert' who cannot be wrong.


Sure I can be wrong.  I'm wrong all the time - it gives me an
opportunity to
learn.  And I'm not the one who claims to be an "expert" Craig.  Let
the
readers of this thread look at my site and then yours to make that
comparison.  The actual proof in one's capacity to learn is simple.  No
one
who has actually done this in a meaningful way would ever think that
they
can quantify risk with a formula when they haven't even bothered to
qualify
it.  A child can read volumes of books on how to ride a bicycle and
immerse
themselves in the physics behind balance and force, and the way the
cilia of
the inner ear works to communicate movement to the brain.  But they
will
NEVER learn how to ride until they get on and start pedaling.   Let me
know
when you stop peddling and start to pedal.



The example spanning this is simple, a single SMS based function with
open
access. This example was a trivial example in modelling. Firewalls

and

other
choke points make calculations simpler, multiple paths offer
complexity.
What I see from this is that a lack of understanding = a dangerous
level of
ignorance.


I could not agree with you more, sir.  A lack of understanding does
indeed
equal a dangerous level of ignorance.  Which is why I so look forward
to an
open debate on this subject where I can hopefully intervene on the
adoption
of your formulas when human life is at stake.  Your formulas can't even
be
reliably assigned to the SMS model; to apply them to your CIP
contributions
will certainly be dangerously ignorant.



Like it or not, security is an economic function, pure and simple.
There is
a cost for all actions and at the end of the day, somebody has to

pay.

Perfect security is not a goal, optimal security is. They are not the
same
thing and the later requires better modelling.

Welcome to the future, there will be math.


Fine.  Let's do it this way then.  We'll have someone implement an SMS
solution for banking that we don't have anything to do with.  I'll
assess
risk my way, you assess risk with your calculator.  Since *someone* has
to
pay, are you saying that you are willing to assume responsibility for
financial losses when your numbers come out wrong?

And you actually making my argument for me;  YOU are the one who stated
this
to my question, and I quote:

T: "And just how do you come up with the probability of compromising
the SMS
function and the user authentication method?"
C: "Actually, fairly simply using Bayes' formula."

So which is it?  Is quantifying the probability of compromise "fairly
simple
using a formula" or is it "not an economic function pure and simple?"

T



Regards,
...
Dr. Craig S Wright GSE-Malware, GSE-Compliance, LLM, & ...
Information Defense Pty Ltd



-----Original Message-----
From: Thor (Hammer of God) [mailto:Thor () hammerofgod com]
Sent: Wednesday, 10 February 2010 4:40 AM
To: pen-test () securityfocus com; full-disclosure
Cc: craig.wright () Information-Defense com
Subject: RE: SMS Banking

I'm looping in the FD list because often my replies don't make it to
Pen-Test, and this has hit a nerve with me.

I've looked over your post at:

http://gse-compliance.blogspot.com/2010/02/modelling-risk.html .

Once I was able to get past the overwhelming egoism and self-
substantiating
claims of your contributions to the industry, I arrived at the
conclusion
that the only portion of the aforementioned page that is not complete
drivel
and even laughable to anyone who has actually worked towards
ascertaining
actual risk in production environments, is where you describe your

own

words
as "ravings."  Ravings, of course, means "delirious, irrational
speech."

I'm fine with you sitting back and gloating about the Security Hero
award
you got from Northcutt, but when I see that you are actually
contributing to
ANY level of Critical Infrastructure Protection, it makes me fear for
anyone
who might be counting on your presumed skillset to actually make
intelligent
decisions about risk where human safety is at stake.  Your "risk
formula" is
ridiculous.  What number would your formula have yielded 2 weeks

before

SQL
Slammer was released?  Where is the variable for unpatched systems?
What
number do we plug in for malicious employee factorization?   More
importantly, where is the calculation for self absorbed snake-oil
selling
academics with no real experience using their calculator to come up
with
magic numbers that represent the risk of a nuclear power plant being
hacked?

Since you are (self-described) as "currently the only GIAC GSE
(Compliance)
holder globally and the most highly accredited Global Information
Security
Professional" and thus (presumably, if only in your mind) the

greatest

security mind in the world, how about accepting a challenge to an

open

debate on the subject at Defcon?  People like you are dangerous and
need to
be exposed before someone in a position of power actually believes

that

you
know what you are talking about.  Bring your abacus.

t





-----Original Message-----
From: Craig S. Wright [mailto:craig.wright () Information-Defense com]
Sent: Monday, February 08, 2010 3:40 PM
To: Thor (Hammer of God); pen-test () securityfocus com; security-
basics () securityfocus com
Subject: RE: SMS Banking

" And just how do you come up with the probability of compromising

the

SMS
function and the user authentication method?"

Actually, fairly simply using Bayes' formula.

I have posted on this at:
http://gse-compliance.blogspot.com/2010/02/modelling-risk.html

The comment was that GSM itself can be made more secure if it is
coupled
with another means of securing the transmission.

"if one can position one's self anywhere in the transmission

chain."

This is a select number of locations. It is not everywhere. Though

the

number of locations may be large - it is not infinite. It is also

not

all
points on the globe.

As can be seen in the post, what the effect of an SMS only based
solution is
a time degrading function. This is, the longer that the SMS

application

runs
(alone), the greater the risk until eventually, the risk is

maximised

at
certain failure.

Adding a second function, such as a non-SMS based sub-function can

help

to
mitigate this, but a well chosen sub-function is more effective

alone

without the addition of the SMS measure and hence a better option.

The SMS function alone can befit from a second function, but this

is

only
warranted if the SMS function is an essential process for some

reason.


Regards,
...
Dr. Craig S Wright GSE-Malware, GSE-Compliance, LLM, & ...
Information Defense Pty Ltd


-----Original Message-----
From: listbounce () securityfocus com
[mailto:listbounce () securityfocus com] On
Behalf Of Thor (Hammer of God)
Sent: Tuesday, 9 February 2010 3:15 AM
To: pen-test () securityfocus com; security-basics () securityfocus com
Subject: RE: SMS Banking

And just how do you come up with the probability of compromising

the

SMS
function and the user authentication method?

While little formulas may go well in meetings, this hardly helps

the

OP

with
his question.  You also failed to note that the overall risk figure

you

calculate has to be compared to something - what are you comparing

it

to?
If P(Compromise) turns out to be 42, what does he do with that
information?

Regarding GSM, what "far more" information are you talking about?

The

account number and PIN is all that is needed in the example given

by

the OP,
and that is exactly what one would get from a GSM attack.

You should also note that "compromising GSM" is completely

unnecessary

if
one does in fact have a select number of locations where the actual

GSM

signal is redirected.  Cracking GSM itself does NOT require being

at

a

"select number of locations" if one can position one's self

anywhere

in

the
transmission chain.

t


-----Original Message-----
From: listbounce () securityfocus com
[mailto:listbounce () securityfocus com] On Behalf Of Craig S.

Wright

Sent: Sunday, February 07, 2010 8:06 PM
To: 'Markus Matiaschek'; 'M.D.Mufambisi'
Cc: pen-test () securityfocus com; security-basics () securityfocus com
Subject: RE: SMS Banking

The solution needs to be based on risk.

Where a system uses an SMS response with a separate system (such

as

a

web
page), the probability that the banking user is compromised and a

fraud

is
committed, P(Compromise), can be calculated as:
  P(Compromise) =  P(C.SMS) x P(C.PIN)


Where:    P(C.SMS) is the probability of compromising the SMS
function and
          P(C.PIN) is the compromise of the user authentication
method


The user can be compromised by Trojan apps, poor pins that are

pasted

to a
monitor etc.

P(C.SMS) and P(C.PIN) are statistically independent and hence we

can

simply
multiply these two probability functions to gain P(Compromise).

The

reason
for this is that (at present) the SMS and web functions are not

the

same
process and compromising one does not aid in compromising

another.

With

the
uptake of 4G networks this may change and the function will not

remain

as
simple.

It may be possible to compromise GSM, but the truth is that this

must

be
done from a select number of locations and the attacker also

requires

far
more information than the PIN and account number. This makes the

attack

far
more difficult and far costlier to the attacker.

This also means that the attack has to be targeted in place of

scripted

(as
many bots already are).

On the other hand, the probability that an SMS only system can be
cracked is
simply the P(C.SMS) function and this is far lower than a system

that

deploys multiple methods.

This SMS only means would not be a good means of authentication a

user.

As a
secondary factor, SMS adds complexity. By itself, SMS is a poor

means

of
controlling risk.

Regards,
...
Dr. Craig S Wright GSE-Malware, GSE-Compliance, LLM, & ...
Information Defense Pty Ltd


-----Original Message-----
From: listbounce () securityfocus com
[mailto:listbounce () securityfocus com] On
Behalf Of Markus Matiaschek
Sent: Saturday, 6 February 2010 9:08 AM
To: M.D.Mufambisi
Cc: pen-test () securityfocus com; security-basics () securityfocus com
Subject: Re: SMS Banking

Hi,

I'd just like to make some comments, i didn't think about a

solution

for your problem.

First of all i think that my Budi wibowo got something wrong

regarding

who is sending the PIN.

Second, GSM is cracked: http://reflextor.com/trac/a51 and can be
intercepted and decrypted. You should take this into account.

Third i think the only farely safe way to make money transfers is

with

transaction numbers, TANs. German banks send mobileTANs to
preregistered cell phone numbers to allow a transaction (through
online banking though).
A "three-way-handshake" with a mTAN should pretty much prevent
transactions through spoofed numbers.

regards,
Markus Matiaschek
Absolute IT Consulting S.A.
San José, Costa Rica

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