IoT: When my Home's Thermostat Becomes a Weapon
A Look at the Internet of Things (IoT). Exploring Existing Threats and a Few New Ones.
January 23, 2017
As
 I consider the Internet of Things (IoT), I think of things like 
smart-watches, internet baby cameras, home thermostats, and other neat 
technologies. I recently pondered a broad range of security concerns and
 thought it might be fun to explore these questions a bit further and 
share some thoughts and suggestions. 
What's the security situation with all my cool gadgets? 
My
 home's thermostat is smart and connected to the Internet. This gadget 
is a wonderful innovation and part of the virally expanding portfolio of
 Internet of Things (or IoT) devices. You all know about these, and 
likely have one or many in your own home or apartment. In fact, industry
 studies suggest that each person on the planet will own at least five 
IoT gadgets by 2020. 
 
My
 thermostat allows me to alter my home's temperature and check the 
current settings from the convenience of my cell phone. All cool (pun 
intended), right? Well, this convenience raises some secondary important
 concerns and a completely new set questions. But, hold these particular
 thoughts for a minute. A smart thermostat is technically a system, 
complete with an operating system, a wireless network interface, ability
 to control another system, and it offers configurable settings 
(schedule, override, notifications, etc).
With an operating system; one
 must safeguard the OS against unauthorized access, root kits and 
malware infiltration which can infect the system and alter its intended 
behavior.
With a wireless network interface; one
 must deny access to outsiders or bad actors. In the case of a wireless 
network, let us not forget that a bad actor could hijack your thermostat
 from the seat of their car parked outside your house. However, a bad 
actor would more likely gain access via the internet, either through a 
poorly configured firewall (or no firewall), or via open insecure ports 
on an internet router. Quick question, when was the last time you logged
 into your Internet Router and checked its settings? Thought 
so. Regardless of the method a bad-guy may use to get into your local 
area network (LAN), he or she being there is not good. Once on your LAN 
the bad actor can and will discover every vulnerable device and shared 
file on the LAN including any VPN connections to your employer, for 
which the latter raises some distinct problems and liabilities for both 
the employee and the employer. 
With a device that can control another device; one
 must understand the downstream devices that can be controlled by the 
IoT device (aka, the furnace/AC controlled by the thermostat) and that 
compromising the controlling device (aka, the thermostat) gains 
immediate access to control any downstream controlled-device (aka, the 
furnace/AC system).
With a device that has alterable settings (a configuration table, so to speak); one
 must safeguard the table from unauthorized alteration. But there's one 
challenge with safeguarding these settings on many IoT devices. The last
 time I checked my thermostat there was no password protection. Thus 
once I connect to the thermostat, I can change any setting without 
challenge.
Now,
 let's come back to the point I asked you to hold onto: the cell phone 
app that allows me to control my thermostat from afar. Yes, there is a 
third-party involved between me (my cellphone) and my thermostat. It's 
the thermostat manufacturer's service that connects us. In principle, my
 thermostat connects to the manufacturer, and my cell phone app connects
 to the same place, and we're matched by a lookup code that associates 
us.
What about the thermostat manufacturer?
The
 manufacturer's security infrastructure surrounding this "meeting place"
 becomes one of the most critical components in the mix. I guess I 
really need to trust my thermostat manufacturer, right? Have they 
designed reasonable security into the product? Do they have security 
personnel dedicated to the job and constantly monitoring and testing the
 environment? Have they secured their product development networks and 
customer-portal networks? Lots of questions, few answers come to mind.
 
A
 commercial product manufacturer's network will likely be more secure 
than most home wireless networks. But, it's important you know that we 
as consumers become completely and immediately reliant upon the security
 that the manufacturer has designed their products, and that they 
implemented and applied appropriate layers of security within their 
networks to protect their thermostat (or whatever product) from being 
infiltrated by an outsider. 
I
 don't think very many consumers pay much attention to this aspect of 
certain IoT devices, likely because coolness sometimes overrides the 
messy topic of security. If you think about how rapidly brand new IoT 
technologies and start-ups come onto the scene, you have to wonder: have
 they really implemented a secure infrastructure and hardened their 
products and services to adequately protect your data and your 
network? I don't know about you, but this makes me wonder.
So What Could a Hacked Thermostat Do Anyway?
What
 if my thermostat manufacturer's system or network is hacked? Millions 
of subscribers' thermostats (or worse, the downstream controlled 
furnace) could all be compromised as a result. What if a bad actor were 
to alter the temperature in every smart thermostat to the maximum 
possible setting (say, 99 degrees) and leave it there until you pay the 
ransom? A team at DEF CON demonstrated this very scenario just this past
 summer. Or, what if a bad actor compromised all thermostats to initiate
 a massive distributed denial of service attack on another victim, 
perhaps a targeted business, or Internet DNS servers (which actually 
occurred very recently)?
 
If
 this attack was for the purpose of a ransomware scenario, then the 
sure-fire home solution is to simply shut off the thermostat and replace
 it with a different device or a non-tech variant. This eliminates the 
problem entirely. But this fix is not as easily accomplished in 
commercial businesses or hospitals, where the complexity and impact is 
far greater.
What
 if all the smart thermostats turned on all furnaces at the same time? 
Could this cause a significant measurable drain on our electrical power 
grids? Perhaps, not so much at the present time, because not every home 
has a smart thermostat, nor are they all the same brand of smart 
thermostat. But given the time and the motive, the capability definitely
 exists for a bad actor to infiltrate a broad range of smart thermostat 
brands, business HVAC systems, and other targets, and create a 
coordinated attack through exploitation of many brands of thermostats 
and smart devices. This would become a new type of attack, and certainly
 one that could be categorized as being among the aspirations of nation 
state bad actors rather than being attributed an individual bad actor. 
There are things about things that we just don't yet know.
All these "what-ifs" could actually occur. And, over time, they will in one form or another.  
So, Could My Thermostat Steal My Data? Actually, yes.
There
 are additional concerns beside using thermostats as a ransomeware 
devices, or as "mules" in a distributed denial of service botnet attack 
against a 3rd party. What if a bad actor hacked the thermostat 
manufacturer's network and introduced a malicious thermostat OS update 
with the ability to steal data from devices on your LAN, or the ability 
to spread malware to them? 
Perhaps
 a bad actor configures the hacked thermostat to function normally but 
with an additional malicious feature. What if a hacked thermostat were 
to become a data leakage device sitting inside your LAN with the 
sustained ability to forward every piece of electronic data from every 
device on your LAN (your PCs, your file shares, your media devices, 
etc.) sending it all to a malicious site somewhere in the ether. This 
type of attack may not need to steal data very quickly, but go 
undetected for weeks or perhaps months or years without being detected 
as it siphons data in bits and pieces in a sustained attack. While the 
latter type of attack is a bit more sophisticated in its approach, the 
operating system and technology present in many small micro-controlled 
systems (e.g. Linux and Java) could make the smart thermostat a 
formidable place for such an attack to begin.
In
 a similar manner to the hacked thermostat, what if the bad-actor 
infiltrated the respective cell phone app with a malicious version, with
 the ability harvest all your contacts, credit card info, and other 
sensitive data stored in your cell phone? 
When you think about this, and use your imagination, the possibilities along with the potential nightmares are endless.
 
My Home's LAN is not that interesting to a "bad actor", Right? Wrong.
Actually,
 your home network is pretty interesting to bad actors. Home local area 
networks are changing in many ways. With more connected devices such as 
IoT devices, increased data storage devices (local and cloud connected),
 and media sharing devices, your network is a very interesting place. 
Home network Internet connection speeds have dramatically increased to 
impressive levels, thanks to powerful fiber optics and advanced consumer
 bandwidth plans that rival many commercial business networks. Most home
 networks today boast extremely fast download connection speed (in many 
cases greater than 100Mb). More importantly to the aspect of data theft,
 these also boast the same high-capacity bandwidth for uploads as 
well. Thus, the home owner's local area network may have 100Mb or 
greater down/up with very little security beyond the Internet 
router. Unlike commercial business networks, the home network typically 
does not employ advanced security perimeter controls such as intrusion 
detection systems, data leakage prevention, enforced access control 
policy mechanisms. This is why it is an attractive place for bad actors.
 In other words, once a bad actor gets access past your cable router, 
they would potentially have access to a wide open network, complete with
 an extremely fast Internet connection by which they could establish as 
a beachhead to launch other attacks, and attack you.
Think
 of the many hundreds of millions of home networks out there for a bad 
actor to choose from, most of which are wide open territory. Now think 
of the volume of IoT gadgets out there. Early predictions regarding IoT 
growth reveals that the number of IoT gadgets will reach 20.8 billion devices by 2020 (reference: Gartner, 2015). Intel Security predicted the number to be in the range of 20 to 30 billion devices by 2020.
 That's a lot of IoT devices spanning perhaps billions of relatively 
insecure home networks across the globe. Most recently, security firms 
have adjusted their predictions to nearly 50 billion IoT devices by 
2020. This leads me to wonder: do we really know the prolific potential 
of global IoT sprawl? 
 
A Few Good Steps You Can Take...
Using
 just the above examples we could fill many whiteboards with attack 
profiles and scenarios, line diagrams, and pathways to potentially 
catastrophic damage. And we need to conduct this type of out-of-box 
thinking to get inside the heads of bad-actors to anticipate what they 
are thinking, in order to understand how they operate and adapt. While 
it is unreasonable to think that home users will implement advanced 
security technology found in commercial business networks, there are 
some very good basic steps that everyone can and should consider to 
ensure their security. 
A good first step that home users should consider is locking down your internet gateway (the router) by restricting access with a complex password, disabling external remote management ports, disabling the DMZ function if you don't need one, applying the latest security firmware updates, and restricting inbound ports to only those that you really need. Also, disable inbound ICMP requests (we
 call these ping requests) so that your router doesn't respond to pings 
from the outside. This will provide a level of stealth since your router
 won't answer to pings. Incidentally, a ping request is among the first 
steps a bad actor takes to determine which IP addresses are responsive 
or not. You should also buy and install a good anti-virus/anti-malware 
software for all of your PCs, and keep it enabled and always up to date.
 You should also consider configuring a password on your devices that 
share files (e.g. media, file servers, home PCs, etc).
Lastly,
 it is important to try to maintain a current and reasonable awareness 
about emerging potential security threats and what you can do to 
minimize them. For example, news of recent examples of phishing attacks 
have been shared on the internet, local news and mainstream 
media. Remember to not click on links contained
 in messages from people you don't know. Even when someone you know 
sends an obscure message containing a link or attachment, think twice 
about clicking it since their PC could be compromised and potentially 
trying to spread malware to you and others. 
With
 respect to security and the Internet of Things, I consider myself a 
"cautious IoT embracer" which means, I try to understand and answer as 
many of the questions presented here to understand the risks, and adapt 
my security countermeasures to manage them. Good security and IoT can 
and will coexist. We just need to think creatively and thoroughly as we 
embrace both.
I hope you enjoyed this article and hope it was helpful.
Stay tuned, and stay safe.
Ed