In many of the InfoSec forums I subscribe to people regularly as the "How long is a piece of string" question:
How extensive a risk assessment is required?
It's a perfectly valid question we all have faced, along with the "where do I begin" class of questions.
The ISO-27001 standard lays down some necessities, such as your asset register, but it doesn't tell you the detail necessary. You can choose to say "desktop PCs" as a class without addressing each one, or even addressing the different model. You can say "data centre" without having to enumerate every single component therein.
This kind of question keeps coming up, many people are unclear about the Statement of Applicability on ISO-27000.
The SoA should outline the measures to be taken in order to reduce risks such as those mentioned in Annex A of the standard. These are based on 'Controls'.
But if you are using closed-source products such as those from Microsoft, are you giving up control? Things like validation checks and integrity controls are are 'internal'.
Well, its a bit of a word-play.
- SoA contains exclusions on controls that are not applicable because the organization doesn't deal with these problems (ie ecommerce)
- SoA contains exclusions on controls that pose a threat (and risks arise) but cannot be helped (ie A.12.2 Correct processing in applications) and no measures can be taken to reduce these risks.
With this, a record must be present in risk assessments, stating that the risk (even if it is above minimum accepted risk level) is accepted
The key to the SOA is SCOPE.
On the ISO27000 Forum list, someone asked:
That's a very ingenious way of looking at it!
One way of formulating the risk statement is from the control
objective mentioned in the standard.
Is there any other way out ?
Ingenious aside, I'd be very careful with an approach like this.
Risks and controlsare not, should not, be 1:1.
What framework would you use to provide for quantitative or qualitative risk analysis at both the micro and macro level? I'm asking about a true risk assessment framework not merely a checklist.
Yes, this is a bit of a META-Question. But then its Sunday, a day for contemplation.
When does something like these stop being a check-list and become a framework?
COBIT is very clearly a framework, but not for risk analysis and even the section on risk analysis fits in to a business model rather than a technology model.
ISO-27K is arguably more technology (or at least InfoSec) focused that COBIT, but again risk analysis is only part of what its about. ISO-27K calls itself a standard but in reality its a framework.
The message that these two frameworks send about risk analysis is
Context is Everything
(You expected me to say that, didn't you?)
I'm not sure any RA method works at layer 8 or above. We all know that managers can read our reports and recommendations and ignore them. Or perhaps not read them, since being aware of the risk makes them liable.
Ah. Good point.
On LinkedIn there was a thread asking why banks seem to ignore risk analysis .. presumably because their doing so has brought us to the international financial crisis we're in (though I don't think its that simple).
The trouble is that RA is a bit of a 'hypothetical' exercise.