Starting in 2017, the FDA has said
they intend to require SBOMs for medical devices. Early this year, they
released a draft requirement for comment, saying they planned to finalize a
requirement and make it mandatory by the end of the year.
However, a few weeks ago, I heard
in one of the bi-weekly meetings for the Healthcare SBOM Proof of Concept
(which is now conducted under the auspices of the Healthcare ISAC) that the FDA
had just announced they were going to postpone enforcement of the requirement
until late next year (and moreover, that they weren’t going to allow any
changes to the draft requirements, even though they…ahem!...left a lot to be
desired). Of course, this was disappointing, since there was a lot of agreement
(including among medical device makers) that it’s important to have the SBOM
requirement.
But, in the CISA SBOM Onramps
and Adoption workgroup meeting this week, Josh Corman announced that the Patch
Act had been passed last week in the year-end rush of legislation. This is a
piece of legislation that requires the FDA to mandate cyber protections for
medical devices. It had initially shown promise of being passed, but was
withdrawn without a vote earlier this year. The FDA has 30 days to complete the
rulemaking for this (and I hope they’ll change what they proposed last April),
which seems to indicate it’s on a fast track to implementation. While the Act
doesn’t specifically mandate SBOMs, it lists them as one of the measures that
might be required, and the word is they will be required.
This is important for two reasons.
One is that this will be the first mandatory requirement for SBOMs anywhere in
the world (at least as far as I know). Of course, nobody is advocating such a
mandatory requirement for every software product and device in every industry,
but there are certain cases where mandatory SBOMs are justified. I would say
that medical devices, which literally keep people alive in hospitals, are one
of the best of those cases.
However, in my opinion the second
reason is even more compelling: It’s that intelligent devices in general, not just
medical devices, pose a unique cybersecurity challenge; SBOMs can play a key
role in addressing that challenge.
I had never stumbled upon that
challenge before I and Isaac Dangana, who works for my client Red Alert Labs
(a company based in Paris that focuses on security and compliance for IoT
devices), published this article in the Journal of Innovation last summer. While
that article was primarily intended to be an introduction to SBOMs for people
in the IoT and IIoT worlds who weren’t familiar with the concept, Isaac and I ended
up pointing to a serious issue that affects the ability of a user to secure an
IoT or IIoT device, or even to learn about vulnerabilities that may affect it. In
fact, we ended up making the case – without intending to – that IoT and IIoT
devices may currently be less secure, and are certainly much less transparent
to users, than are “user-managed” software products (i.e. standard software
running on Intel-standard servers).
The problem begins with the fact
that IoT and IIoT devices are intentionally sealed. The results of this include
the fact that users can’t identify by themselves the software products
installed in the device, and they can’t update or patch any of the individual
software packages in the device.
Instead, all the software in the
device is treated as a single “lump” (to quote a friend who manages
cybersecurity for the thousands of medical devices installed at a large
hospital chain). The device comes with all the required software installed, and
patches or updates to individual software products in the device are held until
the next scheduled device update – at which point the entire “lump” is replaced
as a unit, often at night via an internet connection.
Of course, for a network administrator
who runs him or herself ragged, trying to keep up with vulnerabilities found in
the hodgepodge of software products running on the servers they’re responsible
for - as well as trying to apply the never-ending stream of patches to software
products installed on those servers - the idea that all responsibility for
vulnerability management and patching would be completely taken out of their
hands and assigned to some gremlins that expect neither pay nor recognition
must seem like heaven on earth.
However, this is only heaven on
earth if the device user has complete confidence that the device manufacturer
will:
a)
Monitor each software
product installed in the device for vulnerabilities and “coordinate with” (i.e.
bug the hell out of) the software product’s supplier to make sure they expeditiously
patch any serious vulnerabilities in it.
b)
Require the supplier
of at least every “top level” software product installed in the device to
provide an SBOM for their software and update the SBOM whenever they release an
update or patch for that software.
c)
Using the SBOMs, track
components in each of the software products installed in the device and identify
vulnerabilities applicable to each component.
d)
Require each software
supplier to provide VEX notifications, which will let them know about component
vulnerabilities that aren’t in fact exploitable in the product and prevent
their wasting a lot of time chasing down non-existent vulnerabilities.
e)
Whenever a serious
vulnerability can’t be patched immediately, provide a notification to all the
customers of the device regarding mitigations they should apply to make it less
likely that the vulnerability will be used to compromise the device.
f)
If one of the software
products installed in the device has proved to be a “problem child”, with
multiple longstanding vulnerabilities and no commitment by the software’s
supplier to fix those in anything less than the remaining life of the universe,
commit to replacing that software within say three months.
g)
When a software
product has reached end of life status, commit to replacing it within say six
months.
h)
When an open source software
product hasn’t been patched or updated for say six months, admit that the
product is effectively in end of life status and commit to replacing it within six
months - although sooner if there are one or more serious unpatched
vulnerabilities in the product.
i)
Require that the
supplier of each software product installed in the device either attest they
have followed every provision of the NIST Secure Software Development Framework
(SSDF), or identify any provisions they haven’t followed and provide an
explanation of why they haven’t done so.
j)
Etc., etc.
Of course, the device manufacturer
is likely to complain lustily that they can’t stay in business if they’re
really forced to do all of the above, with respect to every software or
firmware product that’s installed in their device. And believe it or not, I agree
that this is too much to ask of them.
However, by the same token, I say
it’s too much to ask of their customers that they stay in Fat, Dumb and Happy
mode, in total ignorance of any security measures that the device manufacturer
took or didn’t take to secure the software within their device. If the manufacturer
isn’t willing to do literally everything possible to secure the device (i.e.,
all of the items listed above), they should at least give their customers the information
they need to learn about the measures they have taken, and express
willingness to have a discussion with any customer who thinks there are
measures the manufacturer should take but hasn’t.
What is the information the end
user should have about the device? First, they need at least a “one-level”
SBOM, showing every software or firmware product installed directly in the
device, along with whatever identifiers are required to look up the software in
the NVD or another vulnerability database like OSS Index. If the customer has
that much, they’ll be at the same point that most users of “user-managed” software
find themselves at, with respect to the software installed on the servers they
operate: They’ll know what software products are directly installed on each device
(or on each server, in the case of user-managed software), and they’ll be able
to investigate vulnerabilities found in those products.
But is that enough? After all, any
server administrator today can identify every software product that’s installed
on their servers using a tool like PowerShell or even Windows™ Explorer; then
they can learn about vulnerabilities in those products by looking them up in
the NVD or another vulnerability database. But they won’t learn about
vulnerabilities caused by components of those software products if they
don’t also have an SBOM for each product; then they can look up each component in
the NVD, to learn about its vulnerabilities.
How will the server administrator
get an SBOM for one of the user-managed software products? They’ll probably ask
the software’s supplier for it, and they’re likely to get it, too (at least one
SBOM, anyway). Why is the product’s supplier likely to give it to them? Because
they’re a customer, of course.
However, if an IoT or IIoT device manufacturer
gives a customer a first level SBOM for the device, the customer will just know
the names of the software products installed in the device – the equivalent of what
they could learn from running Windows Explorer on a standalone server. The IoT
customer won’t know anything about components of those products, unless they
have an SBOM from the supplier of each software product installed in the device.
At least, having a first level
SBOM, the device customer will know the names of the software products
installed in the device and their suppliers’ names. What will they hear when
they contact those suppliers to ask for an SBOM? Most likely nothing at all, or
perhaps “Get lost”. The problem is that the device customer isn’t a customer of
the suppliers of the software installed in the device; the device manufacturer
is. It’s very likely that only the manufacturer will be able to get the SBOMs,
and perhaps not even them..
Thus, it isn’t likely that IoT or
IIoT device customers will be able to obtain SBOMs for software products
installed in intelligent devices they own or utilize. Of course, they can beg
the device’s manufacturer to please, pretty please get the SBOMs for them – but
I doubt that will be a very productive exercise.
But more generally, why should
analysis of cyber risks found in intelligent devices be exclusively the
responsibility of end users? After all, the manufacturer chose the “first level”
software and firmware products that are installed in the device. It’s their job
to make sure they’re secure; if they’re not, it’s the manufacturer’s
responsibility either to get the supplier to fix vulnerabilities in their
software, or to replace the software with a more reliable product.
But how can the device customer even
“audit” the manufacturer’s performance in vulnerability management? If the
customer receives an SBOM that lists the first-level software and firmware
products installed in the device (which will hopefully start happening soon
with medical devices), that at least puts the device customer on the same level
as the server administrator that identifies each software product installed on
their server using Windows Explorer: The device customer will usually be able
to learn about vulnerabilities in those products, although they won’t learn
about vulnerabilities found in the immediate components (dependencies) of those
products.
However, why should the device
customer even have to look up vulnerabilities in each of the “first-level” software
and firmware products installed in the device? Each customer presumably has
exactly the same set of software products installed in their device as any
other customer does. If there are say 10,000 customers of a device, why should
every one of them have to perform exactly the same set of steps to learn about
vulnerabilities in the device, when the manufacturer can perform those steps
for all 10,000 customers at once?
And not only can the manufacturer
perform those steps themselves, but they should be performing them already.
That is, they should be doing it, assuming they care about securing the devices
they sell. For example, if there are say 15 software and firmware products directly
installed in the device (there may be a lot more, of course), why can’t the manufacturer
share with their customers every exploitable vulnerability associated with
those products?
Besides reporting each
vulnerability to their customers, the manufacturer also needs to register the device
itself in the National Vulnerability Database (NVD) and report all exploitable
vulnerabilities they identify in the device. This includes both vulnerabilities
due to code written by the manufacturer and vulnerabilities due to code written
by the suppliers of the third party software and firmware products installed in
the device.
When device manufacturers start
doing this, vulnerability management for intelligent devices, including medical
devices, will be much easier. The customer will just have to search on the
device’s CPE name in the NVD, in order to learn about all exploitable
vulnerabilities in the device. This is what software users are supposed to be
able to do now. Why shouldn’t device users be able to do the same thing?
I hope the FDA includes this in
their device security requirements, along with requiring an SBOM for the device.
Any opinions expressed in this
blog post are strictly mine and are not necessarily shared by any of the
clients of Tom Alrich LLC. If you would
like to comment on what you have read here, I would love to hear from you.
Please email me at tom@tomalrich.com.
No comments:
Post a Comment