Tuesday, May 16, 2017

What Systems Should be in Scope for CIP?

In my post yesterday, my second on Wannacry, I was addressing the emergency patches made available on Friday for Windows XP, Vista and Server 2003 – all out-of-support operating systems. While I had already published a “Public Service Announcement” on the need to apply that patch on all systems at High and Medium impact assets in scope for CIP, an auditor had emailed me to point out that, for security not compliance reasons, the patch should be applied to all devices on the OT network that run one of the three old OS; this includes devices found in Low impact assets, Distribution substations and generating plants that are below the threshold for inclusion in the BES. The auditor’s reasoning for suggesting this was good: Just because these devices aren’t directly networked with Cyber Assets in scope for CIP (if they were directly networked, they’d at least be PCAs), if they become infected with Wannacry they will still pose a substantial risk to the BES.

Of course, many NERC entities will argue that they already have great defenses protecting their networks subject to CIP – those in High and Medium impact Control Centers, and in Medium impact substations and generating stations – from their networks that aren’t subject to CIP. And I’m sure this is almost always the case, to a large degree due to CIP, which does require thorough separation of ESPs from other networks. But this didn’t deter the auditor from still advocating (coming as close to “requiring” as he could) that the discontinued OS’s on non-ESP networks also should be patched.

And the reason for this is simple: There is no such thing as a 100% effective security measure. For a threat as serious as the one posed by Wannacry, however small the chance that it could spread from say a distribution substation to a High impact Control Center, almost any security measure would be justified to prevent that from happening.

But if this is the case, why aren’t these other systems subject to CIP? If there’s even a small chance that they could be the vector for an attack like Wannacry that could lead to a serious event on the Bulk Electric System, shouldn’t there be at least some protections (e.g. patching, in the event of a serious threat like Wannacry) that would apply to them?

Or to use another attack as an example, the Ukraine attacks in December 2015 didn’t originate on the OT network; they started with phishing emails opened by people who had no connection at all to actual operations. Yet by opening these emails, these people inadvertently made it possible for the attackers to have free rein of the IT network and search diligently for a way to get into the OT network – which they inevitably found.

As I’ve said before, I do think IT assets need to be included in CIP in some way. I also believe that non-CIP OT assets (such as the ones discussed above with reference to patching) should also be included. More generally, I think that every cyber asset either owned or controlled by the NERC entity should be included in scope for CIP. But there are a few caveats to that:

  1. I certainly don’t want these new assets to be treated as BES Cyber Systems or Protected Cyber Assets. This would impose a huge burden on NERC entities, for a much-less-than-proportional benefit.
  2. The only way the new assets should be included is if CIP – and the enforcement regime that goes with it – is totally rewritten, along the lines of the six principles I discussed in this post.
  3. My fifth principle is “Mitigations need to apply to all assets and cyber assets in the entity’s control, although the degree of mitigation required will depend on the risk that misuse or loss of the particular asset or cyber asset poses to the process being protected.” In practice, I think there need to be at least two categories[i] of cyber assets in scope: direct and indirect impact. Direct impact cyber assets are those whose loss or misuse would immediately impact the BES; these are essentially BCS, but I would of course change the definition to fix some of the current problems. Indirect impact cyber assets are those that can never themselves directly impact the BES but can facilitate an attacker, as happened in the Ukraine (and as would have happened had any utilities been compromised by WannaCry – since their OT networks aren’t connected to the Internet, the initial infection would have been on the IT network). Essentially, all systems on the IT network, as well as systems at Low impact BES assets and at Distribution assets, would fall into this category.[ii]

As I said in my Wannacry post from Friday, I’m now leaning more to the idea of having a separate agency - within probably DHS - regulate cyber security of critical infrastructure. This includes the power industry, oil and gas pipelines, water systems, chemical plants, etc. I’m not doing this to punish NERC, but because I believe there will be a lot of advantages to having one regulator overseeing all of these industries, as opposed to separate regulators for each one. For one thing, there would be a lot of synergies, since the similarities among critical infrastructure in these industries are much greater than the differences between them (for example, if you look at my six principles, you’ll see they don’t refer to power at all). For another, I think the power industry, which has had by far the most experience with cyber regulation, would be in a good position to share their lessons learned with the others.

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

[i][i] Note these categories don’t have anything to do with the High, Medium and Low impact categories in the current CIP v5/6/7 (and soon 8!). As I pointed out it seems like 50 times a few years ago when I was digging into the swamp known as CIP-002-5.1 R1 and Attachment 1, those are really not categories of BES Cyber Systems (even though they are identified as such in the requirement); they’re categories of BES assets (substations, etc). I think I first pointed this out when FERC issued their NOPR saying they’d approve CIP v5 in April 2013 (see footnote vii as well as my response to the first comment at the end of the post).

[ii] I’m not ruling out the possibility that there might need to be other categories, or sub-categories of these two.

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