Friday, May 5, 2017

The News from RF, Part II: As Usual, Lew Hits the Nail on the Head

I have already said that Reliability First’s CIP workshop two weeks ago was the best regional CIP meeting I have attended. Probably the highlight of the meeting for me was the joint presentation by Lew Folkerth of RF and Felek Abbas of NERC (you can find their slides here, in the single file that includes all of the day’s presentations. Their slides begin at slide 19). I’ll have at least a few more posts on points that were made by Lew or Felek.

Lew addressed a number of interesting topics, including the RSAW for the new CIP-003-7 standard; of course, the standard itself is awaiting FERC approval. One of his points was a real lightbulb moment for me, which I’d like to share here. On slide 68 in the second section, Lew listed what the new RSAW says regarding auditing Attachment 1, Section 5 of CIP-003-7 (this is the new requirement that addresses Transient Cyber Assets used at Low impact assets): “For Transient Cyber Assets managed by the Responsible Entity in an ongoing manner, verify that the Transient Cyber Assets have an effective means of mitigating the risk of the introduction of malicious code onto the Transient Cyber Asset.”

Lew emphasized the word “effective”, then pointed out that he thought this is really the key to auditing non-prescriptive, results-based requirements (although I prefer the term “objectives-based[i]”), such as this one. That is, since this type of requirement only specifies an objective that needs to be met, not the method to achieve it, there has to be some criterion that the auditor uses to determine what is an acceptable method and what is not.

For example, in CIP-007 R3 (another objectives-based requirement), the entity is required to achieve the objective of mitigating the threat posed by malware to BCS. Suppose an SME at an entity told the auditor that, based on the advice of his brother-in-law, his method of mitigating the malware threat to one or more BCS is to say a certain chant every morning at 7 AM. I think the auditor would be justified in finding the entity in violation - not just issue an Area of Concern, as might be the case if the entity had chosen IDS signatures over anti-virus or application whitelisting methodologies. In the latter case, the auditor might issue an Area of Concern and ask the entity to either justify this decision or implement a different solution. IDS signatures are a plausible methodology for effectively mitigating the malware threat, whereas chants are not (and please don’t send me emails arguing why chants are probably likely to be as effective as IDS signatures! I pride myself on having a fairly open mind, but I do have my limits).

Lew wrote an article about auditing non-prescriptive CIP requirements for the January/February RF newsletter, and I wrote about that article in my own post. I just checked to see how the use of “effective” as a criterion fits into what he said in that article. He lists four components of a good evidence package for the requirement he wrote about in that article, CIP-010-2 R4 (of course, another non-prescriptive requirement). The third component is that the plan must show “how methods documented in the plan achieve the objectives” (the “plan” Lew refers to is the one required by R4. You could say that the plan is the same thing as the objective of this requirement).

Of course, the word “effective” isn’t in here, but I would argue that “methods that achieve the objective” is the same thing as saying “effective methods for achieving the objective”. So I call this a match (not that I would hold it against Lew if his thinking had evolved since he wrote the article. My thinking is always evolving - to put it kindly - and my unofficial motto is “Often wrong, but never in doubt!”).

To sum up this post, I think that the word “effective” (or an equivalent word or phrase) should be understood (and if possible, explicitly stated) in every non-prescriptive, objective-based requirement. This will effectively (I couldn’t help that one. Sorry) indicate that the entity must not just utilize one or more methods to achieve the objective, but that the chosen method must be effective. Of course, none of the current non-prescriptive CIP requirements (such as CIP-010 R4 and CIP-007 R3) currently use this word, but I imagine the RSAWs effectively (OK, I did it again!) remediate that omission. In any case, you should always understand that this word is at least implicitly in place.

As a postscript, I want to point out that one questioner at the RF CIP workshop implied to Lew that the use of the word “effective” would increase use of “auditor discretion”, and thus was a bad thing. I can’t remember Lew’s answer, but I know my answer – if I were in Lew’s place - would be: “The fact that this requirement is non-prescriptive means auditor discretion will definitely be required, whether or not the word ‘effective’ (or its equivalent) is present in the requirement – and the decision to make the requirement non-prescriptive was made by the Standards Drafting Team, not me. However, as I discussed in this post, auditor discretion is already required to audit most of the current CIP v5 and v6 requirements – both prescriptive and non-prescriptive - due to the presence of many ambiguities and missing definitions. The auditor is expected (perhaps with assistance from the Regional Entity) to use whatever training they have in legal logic to audit in spite of these flaws.

“The difference with non-prescriptive requirements is that the auditor is required to use discretion regarding matters of cyber security, including making judgments about whether the entity has used an effective methodology for addressing a particular requirement. Since the auditors are chosen for their posts in part because of cyber security expertise, not legal training, I think it is much preferable to have them exercising judgment in cyber issues, rather than legal/logical ones. But in any case, non-prescriptive requirements are clearly here to stay. No CIP drafting team has drafted prescriptive requirements since v5; I predict that no more will be drafted, regardless of what happens with the current prescriptive requirements[ii] and the current compliance regime.”

Note: When I showed a draft of this post to Lew, he commented that he wasn’t sure what his answer was, but he should have referred to GAGAS, which requires use of professional judgment when performing audits. So his answer would be something like “Use of professional judgment isn’t the exception in auditing, but the rule. Even the “Bible” of our profession requires that we exercise professional judgment, since no requirement ever perfectly addresses every possible case you may throw at it.” Amen.

The views and opinions expressed here are my own and don’t necessarily represent the views or opinions of Deloitte.

[i] After reading a draft of this post, Lew commented that he prefers this term as well.

[ii] I used to view the current CIP v5 and v6 requirements as being almost entirely prescriptive, except for a few notable exceptions like CIP-007 R3 and CIP-010 R4. I now think that the majority of the current requirements and requirement parts are non-prescriptive, perhaps the great majority. I hope to sit down in the not-too-distant future and determine whether each requirement and/or requirement part is prescriptive or not. However, in my opinion there are a few very prescriptive requirements – including CIP-007 R2 and CIP-010 R1 – that require NERC entities to devote inordinate amounts of resources to them, way out of proportion to whatever benefits they provide. 

No comments:

Post a Comment