The turtle, protected by its laborious shell, is an effective metaphor for the safety mannequin utilized in most industrial networks. The economic DMZ (iDMZ) is the shell that protects the mushy, weak heart—the commercial management programs (ICS) the enterprise depends upon.
However whereas the iDMZ blocks most threats, some will inevitably slip by. Once they do, they’ll transfer sideways from system to system, doubtlessly inflicting downtime and knowledge leakage. Giving site visitors free rein as soon as it makes it previous the iDMZ conflicts with the zero-trust safety precept to by no means belief, all the time confirm. And as corporations look to “digitize” manufacturing and apply extra cloud-based providers often known as Trade 4.0, extra units want entry to manufacturing programs.
The reply is micro-segmentation—however there’s a barrier
You may restrict the unfold of malware that makes it previous the iDMZ utilizing a method referred to as micro-segmentation. The thought is to tightly prohibit which units can talk and what they’ll say, confining the harm from cyberattacks to the fewest variety of units. It’s an instance of zero-trust in motion: as an alternative of taking it on religion that units solely discuss to one another for respectable causes, you lay down the principles. An HVAC system shouldn’t be speaking to a robotic, for instance. Whether it is, the HVAC system could have been commandeered by a foul actor who’s now traipsing by the community to disrupt programs or exfiltrate data.
So why isn’t each industrial group already utilizing micro-segmentation? The barrier I hear most frequently from our clients is an absence of safety visibility. To micro-segment your community you might want to know each system related to your community, which different units and programs it wants to speak to, and which protocols are in use. Missing this visibility can result in overly permissive insurance policies, rising the assault floor. Simply as dangerous, you would possibly inadvertently block vital device-to-device site visitors, disrupting manufacturing.
Acquire visibility into what’s on the community and the way they’re speaking
Excellent news: Cisco and our companion Rockwell Automation have built-in safety visibility into our Converged Plantwide Ethernet (CPwE) validated design. With Cisco Cyber Imaginative and prescient you possibly can rapidly see what’s in your community, which programs discuss to one another, and what they’re saying. One buyer informed me he realized from Cyber Imaginative and prescient that a few of his units had a hidden mobile backdoor!
Safety visibility has three massive payoffs. One is consciousness of threats like that backdoor, or suspicious communications patterns just like the HVAC system speaking to the robotic. One other profit is offering the knowledge you might want to create micro-segments. Lastly, visibility can doubtlessly decrease your cyber insurance coverage premiums. Some insurers offer you a reduction or will improve protection limits should you can present you realize what’s related to your community.
Visibility units the stage for micro-segmentation
When you perceive which units have a respectable want to speak, explicitly enable these communications by creating micro-segments, outlined by the ISA/IEC 62443 customary. Right here’s a good clarification of how micro-segments work. Briefly, you create zones containing a bunch of units with comparable safety necessities, a transparent bodily border, and the necessity to discuss to one another. Conduits are the communication mechanisms (e.g. VLANs, routers, entry lists, and so forth.) that enable or block communication between zones. On this method, a menace that will get into one zone can’t simply transfer to a different.
Each Cisco and Rockwell Automation present instruments for segmenting the community. Use Cisco Id Companies Engine (ISE) for units that talk through any industrial protocol, together with HTTP, SSH, telnet, CIP, UDP, ICMP, and so forth. To your CIP units, you possibly can implement even tighter controls over site visitors move utilizing Rockwell Automation’s CIP Safety, which secures manufacturing networks on the software degree. Now we have a number of Cisco Validated Designs (CVDs) on a variety of safety subjects, many collectively developed and examined with Rockwell. Examples of our collaboration with Rockwell embrace Converged Plantwide Ethernet, or CPwE, and the lately added Safety Visibility for CPwE primarily based on Cisco Cyber Imaginative and prescient.
A lesson from nature
Combining an iDMZ with micro-segmentation is like mixing the protecting talents of a turtle and a lizard. Just like the turtle’s shell, the iDMZ helps preserve predators out. And like lizards who can drop their tails if a predator will get maintain, micro-segmentation limits harm from an assault.
Backside line: To get began with micro-segmentation—and doubtlessly decrease your cyber insurance coverage premiums—use Cyber Imaginative and prescient to see what units are in your community and what they’re saying.
To study extra about how Cisco and Rockwell may help strengthen OT/ICS safety with visibility for CPwE, be a part of us for a webinar on November 14. Register right here.