Server Security

Supply Chain Compromises in the News: From Scanners to Servers

Today’s breaking news uncovered by threat researchers at TrapX Security involves compromised firmware in handheld scanners being used to compromise corporate networks.  The attack appears to have used sophisticated malware embedded in the mobile scanner firmware that subsequently targeted servers inside the enterprise. According to the Dark Reading article, “A Chinese manufacturer that sells the popular devices for scanning items shipped or transported apparently has been implanting the malware in its products”.

Todd Thiemann

Todd Thiemann

This new report of a supply chain attack is something that the US Department of Defense (DOD) Defense Science Board warned about.  What I find interesting in this particular attack is 1) the supply chain approach and 2) the sophistication (malware in the handheld scanners that then launched against servers).

This attack is in a similar vein to the NSA’s Tailored Access Operations (TAO) catalog of exploits.   It is a matter of time before bad guys profit using techniques pioneered by sophisticated state actors (if they are not doing so already).

It is a small step for the attack technique using handheld scanners to be applied against servers.  For example, a compromised NIC from China gets slotted into a server and exposes an organization’s sensitive data.  

While today’s news involved handheld scanners, tomorrows news could involve other IT supply chain elements.  Enterprises need to consider validating the integrity of the components coming through their IT supply chain.  What can a savvy IT security person do to avoid these sorts of threats going against server infrastructure?  As Gartner analyst Joerg Fritsch and Mario DeBoer highlighted in recent research, you need to validate server integrity to bootstrap trust as well as consider runtime security controls.  

Gartner Research on IaaS Encryption: Protect your Keys

Todd Thiemann

Todd Thiemann

Gartner analyst Joerg Fritsch published a new report last week titled “Enabling High-Risk Services in the Public Cloud With IaaS Encryption”. It provides juicy insights into the ins and outs of Infrastructure-as-a-Service (IaaS) encryption, trade-offs between data confidentiality and reliability, and provides a nice comparison table of vendor options.  And I am delighted that the research includes a PrivateCore vCage mention!  PrivateCore is the only significant new defensive technology mentioned alongside traditional technologies from legacy vendors.

A point that Joerg highlights in a blog post announcing the report is, “Parts of the confidential data must always be in cleartext in RAM, – even the necessary encryption keys!”  Even if an enterprise uses encryption in the IaaS cloud where they control the keys, at the end of the day those keys need to be in clear text in memory for processing.  A bad guy (outside hacker, malicious insider, etc.) can grab the memory and parse the contents to get encryption keys and decrypt data. Also, your favorite government agency (FBI, etc) that can provide a national security letter requesting the encrypted data and a memory snapshot, parse the memory to get the encryption keys, and decrypt the encrypted data-at-rest.  This is where PrivateCore can help by encrypting memory.

The public cloud has some compelling advantages in speed and deployment, but enterprises need to grapple with the resulting data security issues explained in the Gartner research.  If you want to use the cloud with some comfort that the CSP insiders, hackers, or lawful outsiders cannot grab your memory to view cleartext, it is time for your to consider vCage Host.

OpenStack Summit May 2014 – Security Insights

Oded Horovitz

Oded Horovitz

What an exciting event! This was my first time participating in the OpenStack Summit series, and the May 2014 summit was located in hot and rainy Atlanta

GA left me with sense of being part of something big, and a strong desire to participate in the upcoming event (and not just because of the Paris location). As you entered the event, you could see the sponsor wall proudly presenting PrivateCore among many great OpenStack companies.


The show floor was very busy, and the casual dress code suggested this is going to be a fun event, where I would get my fair share of geeking out time. As you can read below, I wasn’t disappointed.

OpenStack is a growing force as indicated by the bi-annual user-survey.  And the survey tracks Dev/QA, PoC, and Production deployment stages independently. Thank you OpenStack community for some great information!

Lets talk Security

Being a founder of a security company, I have a slight security bias, and the first two days offered a wealth of security-related talks. Below are some notes that I thought might be interesting to PrivateCore blog readers.

Russell Haering talk on Multi-Tenant Bare Metal Provisioning with Ironic triggered a set of question around firmware security. The problem presented by several attendees is the following: “how could one detect or prevent a bare metal tenant attempt to reflash the BIOS firmware or any other IO-device firmware?”.  My best recommendation for detecting firmware updates that will run on the main CPU is to take advantage of the Trusted Platform Module (TPM) chip on your servers to validate the firmware before any sensitive data touches the server. Our vCage Manager can be of help here. As for IO-device firmware, unfortunately, the answer is not as simple, and my design assumption is assume these IO-devices as malicious, and build your stack to defend against them.

Next was the Bryan D Payne talk on Security for Private OpenStack clouds. The talk was more of an open discussion with OpenStack operators rather than a presentation, providing the opportunity to hear back from the community about their best practices. What caught my attention was a comment from one of the security operators at Yahoo. His claim (if I understood correctly) was that they assume every guest VM will be compromised. So far no big news. Then he added that they assume compromised guest VMs will successfully escape to the hypervisor. Now that is some bold statement. Later he explained to me that through Nova message signing, even compromised hypervisors do not have much of a say on their Control Plane. Unfortunately, our conversation was interrupted, and I was left without understanding the full architecture, I hope to catch up with him back in the Bay Area.

While walking the expo floor I had a chance encounter at the demo theater with an interesting technology from HGST. OpenStackSummitATL-HGST As you can see, HGST is working on an open architecture, turning a hard-disk into a Linux server. The hard-disk has a dedicated CPU, memory and ethernet port. It runs Linux, and allows applications such as distributed file-system to run directly on the disk, saving CPU cycles, and all related trips on the server bus. My interest in this advancement relates to the possibility of turning this into an “hardware implant for script-kiddies”. In my blog earlier this year, I touched on a leaked NSA software implant called IRATEMONK – a firmware implant affecting many vendor hard-disk controllers, and allowing a stealthy MBR code injection. With the new work from HGST, anyone capable of writing a Linux application will likely be able to do the same. Technology innovation frequently happens without considering the security implications.

The Marketplace

As sponsors of the event we had a spaceOpenStackSummitATL-OH-AN-booth-small to present our warez, and had many lively discussions with the summit crowd. To my pleasant surprise, most attendees we spoke with understood TPMs, Intel Trusted Execution Technology (Intel TXT) and general Trusted Computing concepts. This resulted  in lots of deep discussions about implementation of the technology in their environment – the OpenStack crowd understood the value of system integrity controls that PrivateCore brings to OpenStack.

Peek into PrivateCore roadmap

If you had a chance to join Keith Basil TripleO talk, you should have noticed the slide OpenStackSummitATL-TripleO-KeithBshowcasing PrivateCore’s technology integration into OpenStack on OpenStack (TripleO). We have not publicly shared details of integration, but if you are interested learning how trusted computing plays directly into cloud deployment and management, please get in contact with us for a preview.

See you all at November’s OpenStack Summit in Paris!

Gartner Report Illuminates Server Security

Gartner’s analysts Joerg Fritsch and Mario de Boer published a comprehensive report covering server security on 31 March 2014 titled “The Feasibility of Host-Based Controls and the Evolution of Server Security”.  This report (G00260437) is a tour de force on all aspects of physical and virtual server security – if you are in the business of securing enterprise server infrastructure, you should get ahold of it and spend some quality time digesting it.  This report is a great example of the value of a Gartner IT Pro service subscription.

Todd Thiemann

Todd Thiemann

The report is holistic and touches on all aspects of server security, including anti-malware (AV), host-based intrusion prevention (IDS/IPS), application whitelisting, file integrity monitoring (FIM), privileged account monitoring and server integrity.

Something that we are proud of is the recognition given to PrivateCore vCage Manager as a leading solution for bootstrapping trust in private and public clouds.  As Gartner states in the report, “…bootstrapped trust comes in with a very moderate price tag, or it could even be a feature of products that are already deployed in the local data center, such as the HyTrust appliance, PrivateCore vCage Manager or OpenStack.”

Reading between the lines, I suspect the recent news regarding NSA’s Tailored Access Operations (TAO) unit is motivating more focus on system integrity.  As Oded pointed out in his January blog post, bad guys will eventually learn from the NSA TAO techniques for illicit gain.  The Gartner Server Security report lays out best practices in securing such systems.  As you look to implement such best practices described by Gartner, have a chat with us about maintaining Linux/OpenStack system integrity with PrivateCore vCage.

Cybercriminals Coming to Firmware Near You

Firmware compromises are starting to make their way into the mainstream news media and are expected to proliferate in the wild.  Oded (PrivateCore’s CEO) prognosticated in an post in early January that cybercriminals would learn from the very skilled NSA ANT technologists to manipulate firmware in their effort to make illicit profits.  Others now share that view.  

Todd Thiemann

Todd Thiemann

In reading yesterday’s New York Times, I came across an article based on CrowdStrike threat research that included the quote, “As security software becomes more prolific, hackers continue to make their way down the food chain to computer hardware where it is much more difficult to identify and remove.”

The details behind security breaches take time to make their way into the news.  I expect that we will eventually read about firmware compromises in the future, but it will take some time before such breach details make their way into the media.  

While compromised hardware and firmware might be difficult to identify, that is the hard problem that PrivateCore has focused on since our founding in 2011.  New threats require new countermeasures.  Hardware and firmware attacks call for a new layer of defense, and PrivateCore provides that layer of defense.  If you are an enterprise IT security concerned about trusted computing for your servers, you should take PrivateCore vCage software for a spin.

Preventing the Next Target* Breach with Trusted Computing

* Replace Target with your favorite retail chain.

Alon Nafta

Alon Nafta

The recent news that Target, Neiman Marcus and perhaps three other retailers suffered breaches involving large volumes of data pilfered is raising concerns among retail security professionals.  While details are sketchy and there are plenty of unknowns, it appears that “memory scraping” (also called “RAM scraping”) malware might have played a part in the compromise. There is plenty of research and alerts around memory scraping malware found here, here and here.  This sort of malware has been around a while – check out this Dark Reading article from 2009 and this 2009 Verizon Data Breach Investigations piece.

What is memory-scraping malware?  What we have seen to date has affected retail point-of-sale (POS) systems and potentially backend systems that are processing various types of payment cards (credit cards, debit cards, prepaid cards, etc.). While standards like the Payment Card Industry Data Security Standard (PCI DSS) call for encrypting cardholder information while at rest (storage) and in transit (in motion on the network), cardholder information is typically unencrypted while in use (memory).  If you can access the POS system or server memory, you can extract its contents including the cardholder information.

The data format of such information is clearly defined (see ISO/IEC 7813 and 7816), so attackers can simply implement suitable algorithms in malware which is then installed on the POS machines to harvest cardholder information in memory with those formats in mind.

How can you protect against this sort malware? Antivirus is certainly a necessary component required by PCI DSS for systems handling cardholder information, but AV has been demonstrated to be less than effective in stopping sophisticated threats and updating AV on isolated networks is cumbersome.

One promising countermeasure is attestation. Attestation protects against persistent malware on immutable, “gold” base software images, and ensures – using cryptographic principles and components – that both hardware and software are unchanged.  Attesting to the integrity of server and POS systems would validate that the machine (hardware and software) is clean of malware. If a machine was infected, it would fail attestation and could be examined and remediated. Proper attestation supported by strong cryptography would eliminate any chance for otherwise undetected malware persisting.

Naturally, there could be some infection that occurs after attestation that could exploit vulnerabilities, but periodically attested systems (which would typically require a reboot) minimize this window of vulnerability (or opportunity, depending on your perspective). In this situation, malware could infect a machine after it was attested in a known, good state, but that malware would be wiped away the moment the system reboots and that would be validated when the system re-attests.

A normal, stateful machine suffers from malware that can use its hard-drive, or other components, to persist. A stateless machine that relies on a locked-down, base software image and is periodically attested avoids malware that might try burrow its way into a stateful component.  POS systems, as well as transaction processing backend systems, are not intended to run arbitrary code.  Validating (attesting) such systems against a known, good software image would dramatically reduce the window of opportunity for attackers.

Security measures typically require some change in technology and processes. One change of periodically attesting systems is that it would require downtime as systems reboot and applications restart.  The impact of this change could be minimized by rebooting during off hours for POS machines and this could be done in a round-robin fashion among a high-availability (HA) server cluster for mission-critical servers. POS systems are natural candidates for being stateless as they handle stateless data.

No security countermeasure is going to stop all attacks all the time – technology is extremely complex and attackers are very clever.  While details of the exact circumstances around the breaches at Target, Neiman Marcus, and other retailers are still unknown, my speculation is that attesting systems would have reduced the chance of a successful attack and minimized the damage of any successful attack by reducing the attack duration.

2014 Prediction: Smart Cyber Criminals Learn From NSA “Software Implants”

Happy New Year and welcome to 2014!  We are off to a rip-roaring start with news of the NSA’s exploit techniques. Following on Der Spiegel’s revelations about the US National Security Agency (NSA) Tailored Access Operations (TAO) group, the new year brought with it news of specific tools used by the NSA Advanced Network Technology (ANT) division detailed in the catalog of exploits described by Der Spiegel and Wired.

Oded Horovitz

Oded Horovitz

While there is not much enterprises can do to counter the NSA going after a specific target (if they want your sensitive data, they will find a way to get it), the more worrisome issue is the criminal community digesting the news and learning from the masters of system penetration.  You can expect that techniques described in the NSA ANT catalog will soon be used by the hacker community to create similar exploits.   

As mentioned in Todd’s earlier blog post, the NSA technologists have designed their exploits for persistence and use the system BIOS as a launching pad.  These bootkits (referred to as “software implants” in the NSA catalog) are the first thing to load when a system starts and can lock themselves into a privileged background process called “System Management Mode” (SMM) from which they can passively inspect data, or actively inject payloads into the running operating system or hypervisor. Some examples of the NSA persistent software implant approach include:

DEITYBOUNCE (highlighted in Bruce Schneier’s blog) and IRONCHEF (also highlighted in Bruce Schneier’s blog) exploit the x86 server BIOS and utilizing SMM to drop their payloads.

IRATEMONK infects the firmware on a common HDD controller, and performs a Man-in-the-Middle (MITM) attack to inject code into the Master-Boot-Record (MBR) of the system on the fly at boot time.

I founded PrivateCore knowing that these sorts of weaknesses existed in today’s computing infrastructure, and anticipating that hackers will take advantage of these weakness to gain data access and system control. Now that the NSA catalog is out in the open, we have evidence that indeed these weaknesses are being exploited in the wild.

PrivateCore vCage counters all of the BIOS threats to servers described in the NSA catalog.  Why can I make such a broad claim?  We protect servers with some foundation technology: validating the integrity of x86 servers with remote attestation to counter BIOS infection trying to fly under the radar. We follow the motto of “verify then trust” when it comes server integrity. Infected BIOS? Infected MBR? We’ve got our eyes on you! This video describes how PrivateCore vCage does this in an OpenStack environment.  

The NSA ANT catalog is dated 2008 so how come we never heard about a breach using these exploits? If I would have to guess, the NSA has been very diligent in using these tools in a pin-point fashion to go after specific targets. Criminals on the other hand, will not be as discriminating or precise, and you should expect more widespread use of these techniques.  

While techniques described in the NSA ANT catalog were previously in the realm of well-funded state actors, you can expect them to come to a server near you as they become commonplace tools of criminal actors. Verifying (rather than taking for granted) the integrity of your compute infrastructure and having measures in place to counter these sorts of persistent threats will enable you to have a better night’s sleep in 2014.   

The Tao of NSA, Persistent Threats and 2014

As 2013 comes to a close, news from Germany’s Spiegel Online that the NSA Tailored Access Operations (TAO) unit created a toolbox of exploits to compromise systems caught my attention.  Todd’s prediction: this news is a harbinger of infosecurity risks making headlines in 2014 as bad guys learn from the extremely talented NSA.  

Todd Thiemann

Todd Thiemann

The news generated by Mr. Snowden’s disclosures has brought data privacy headlines.  What was different about the Der Spiegel article highlighting the TAO was not only the breadth of exploits, but also the depth and sophistication.  

The sophisticated exploits highlighted in the Spiegel piece were designed for persistence.  These are advanced persistent threats (APTs) – once you are in, can you stay in.  As the article highlights, “the [NSA] ANT developers have a clear preference for planting their malicious code in so-called BIOS, software located on a computer’s motherboard that is the first thing to load when a computer is turned on.”  

Modifying the BIOS bypasses traditional security layers such as antivirus software. Mitigating against threats using such attack vectors requires an additional layer of security to attest the validity of the host system, harden systems against compromise, and secure the underlying data-in-use (as well as data-at-rest and data-in-transit).  This is bad news for enterprises and service providers who need to consider protecting their server infrastructure, but the good news is that there are solutions to shut down this attack vector, notably PrivateCore vCage (my shameless product plug for this post).

The Spiegel news dovetails with a cybersecurity prognostication for 2014 from IT risk and governance auditor Coalfire:“There will be a significant security breach at a cloud service provider that causes a major outage.”  Reading the Spiegel Online article, the “security breach” part might have already happened. Buckle your seatbelts and enjoy 2014.

IPMI and New Challenges in Cloud Server Security

Integrated Platform Management Interface (IPMI) controllers ship on practically every  x86 server, and any large IT monoculture provides an attractive target for bad guys.  While offering increased manageability for cloud servers, the abundance of IPMI controllers in cloud environments poses new threats for cloud users, spanning from remote,  over-the-web exploitation to local network attacks from cohabiting cloud tenants.

Alon Nafta

Alon Nafta

Being enabled and connected by default on many systems, IPMI controllers expose unaware users to various threats, orthogonal to the ones they currently protect against, which mostly relate to malware and web-based attacks.

Often overlooked by administrators, ensuring proper IPMI tenant isolation is a key step in protecting against IPMI-based attacks. We were able to demonstrate the usage of a low-footprint memory scraping tool to collect root passwords, keys and other valuable data from memory of remote servers, using an easy-to-accomplish attack sequence.


IPMI has recently made news headlines following two notable and impressive pieces of security research work: the first by Dan Farmer in January, followed by HD Moore in July. A month ago, Rapid7 disclosed software vulnerabilities in Supermicro server firmware. The combination of these results makes the case for practical remote server exploitation, found affect approximately 35,000 servers and potentially many more.

IPMI 101

IPMI provides on-board hardware and software, allowing remote Command & Control communications to servers. IPMI is implemented in most x86 servers and apparently enabled by default in many of them. Technically, it is handled by an on-board Baseboard Management Controller (BMC). IPMI provides functionality that would otherwise require physical presence: display, keyboard and mouse, virtual media, and power management, even when the machine is shutdown. To grasp what can be done via IPMI, one simply has to imagine that the attacker is standing next to your machine with fingers on the console keyboard. 

Several unique features of IMPI are noteworthy in the context of threat assessment:

  • On many systems, IPMI communication is possible through a single Ethernet port. That means that if it’s enabled (through BIOS), IPMI is exposed to the network the server is functionally using. To be fair, the IPMI BMC would have to be assigned an IP address, but that will usually be taken care of automatically by DHCP, something that is present in most networks. HD Moore and Rapid7 were able to discover 35K exposed IPMI interfaces of solely Supermicro servers. Clearly, potential for widespread damage is huge.
  • There is no open source implementation for IPMI BMC controllers – every vendor makes its own, closed-source implementation. That leaves room for many potential bugs, and very few (responsible) eyes searching for them.
  • Similarly to BIOS updates, IPMI firmware updates are hard to manage, and are in the early stages of being recognized as a viable threat by the compliance and pentesting communities. While BIOS and network equipment firmware updates are covered by compliance standards (e.g. PCI DSS, etc.) and pen testing routines, BMC firmware updates are commonly overlooked. Interestingly  enough, most of them are also Chinese.

Other bad security practices, such as unchanged default passwords and needing Java to communicate with IPMI controllers, as well as weak encryption schemes, are worrisome. PrivateCore identified many vendors utilizing TLS 1.0 with 128-bit RC4-based encryption, widely considered as broken, for connecting to the IPMI HTTPS server. The HTTP server also uses untrusted certificates, making the case for easy-to-fake Man in the Middle (MITM) attacks, exploiting poor administrators running unpatched JAVA clients.

IPMI Exploitation DIY

To demonstrate the relative ease in exploiting a vulnerable server via IPMI, we conducted the following attack exercise in our own network, simulating a typical cloud environment:

  1. Scan for IPMI interfaces: Using nmap, we scanned our network for IPMI controllers, easily discoverable by their unique use of port 623.

  2. Vendor identification: Several servers have been found. Identifying the vendor is easy, simply browse to that IP and look at the displayed server brand logo. Programmatically, than can be implemented by parsing HTTP packets from the IPMI controller.

  3. Connecting to servers: The is a trickier part. Not all servers block entries for wrong credentials, leaving room for brute-force and dictionary attacks. Many servers maintain their default passwords, or use a single password for all servers, mostly due to administrator ignorance or laziness. And then there are vulnerabilities, which PrivateCore (and others) consider to be common.

  4. Attaching virtual media: Attaching virtual media is supported by every IPMI controller, as it is one of its key features. An attacker would need to convert its malicious payload to a bootable CD ISO image, that can then be deployed to the remote server via the IPMI user interface.

  5. Reset: We reset the server using the IPMI power management controls

  6. Collecting memory: We used a small-footprint memory “scraping” tool to remotely collect memory. These two tools – tool_1, tool_2 will do the trick.

  7. Collecting rewards: There is really no need to argue why a full memory dump is not something you want your attackers to have, but one that can be done remotely is a whole new game. Hidden gems in memory, such as root passwords and cryptographic keys, are valuable treasure, allowing easy control without having to restart the server again.


Two caveats:

  1. Error Correcting Code (ECC) memory: Many modern servers use ECC memory, which is zeroed out by the BIOS during boot. Conveniently, some BIOSes allow to disable that function (1 out of 3 vendors in our mini-experiment, all VERY popular).

  2. BIOS patching: BIOS updates are also generally possible, in case the BIOS doesn’t support ECC disable (although obviously this increases the complexity of this attack), or if the BIOS is password-locked.


When running on the cloud, one must trust the cloud provider to maintain good security practices, ensure high isolation between tenants and continuously update their software as well as security mechanisms. As cloud infrastructure scales, the potential attack surface grows, the risk of compromise increases, and control measures are not keeping pace. Large-scale architectures and complicated IT measures are a hidden treasure for attackers who can easily find their way in, commonly by user-made configuration mistakes, reinforced by exploiting server vulnerabilities.

One of the better ways to avoid these issues is changing the game for attackers. Rather than building more walls (or, using a more appropriate metaphor, keep fixing the holes in the existing walls), apply a solution that inherently protects the data by attesting the environment and keeping all data (memory, storage, network traffic) encrypted. At all times.


Can you trust your server hardware?

Steve Weis

Steve Weis

We’ve recently seen a spate of news stories about hardware-based attacks. For instance, two recent attempted bank heists at Bank Santander and Barclay’s involved criminals stealing millions of dollars via malicious hardware devices. More concerning, recently leaked documents indicate that the NSA may have collaborated with hardware manufacturers to subvert cryptographic hardware implementations. Researchers recently proposed new ways to create hardware backdoors at the sub-gate level, making it hard to detect even to someone inspecting circuit layouts. But are these hardware risks relevant to servers that we use in the cloud?

Malicious hardware and your server

Modern servers are comprised of many components: processors (CPUs), memory (RAM), disks, buses, network cards, and human interface devices. Each of these components pass through the hands of manufacturers, vendors, supply chains, integrators, and service personnel before ultimately ending up inside servers processing your sensitive data. That server itself may be housed off-premise or be leased from another organization, such as a cloud service provider. Most organization rely on at least some servers that are outside their physical control.

The risk with this loss of control is that is that anyone with access to those components, at any moment in time, could compromise a component or substitute a malicious device in its place. There are many well known boot integrity vector attacks where an attacker could subvert firmware in a system, for example the “Evil Maid Attack”.

Network cards are particularly risky since they have Direct Memory Access (DMA) to all system memory and can exfiltrate stolen data over the network. Some network devices have been found to have remotely exploitable vulnerabilities that allow an attacker to take control of the card and subsequently the host system.

Memory is the new disk

Enterprises are increasingly adopting in-memory architectures to reduce application latency. However, as in-memory architectures become more common, more sensitive data is persisted in memory for long periods of time. While commonly used RAM is generally volatile, it can actually persist its contents after a system loses power. This allows an attacker to literally freeze memory and read its contents in what’s called a “cold boot” attack.

More worrisome, RAM is becoming more persistent with technologies like non-volatile memory in DDR3 form factors. By design, these memory technologies persist contents of memory when power is lost — just like a disk. Attackers could simply walk away with a memory DIMM containing not only private data and software, but also critical cryptographic keys used to secure data at-rest encryption.

Reducing the security perimeter

PrivateCore’s philosophy to addressing vulnerabilities in hardware and the risk of persistent memory is to minimize the number of components that users must trust in a server. With today’s technology, it’s possible to reduce a server’s security boundary to just one component: the CPU. From just the CPU, it’s possible to establish a trusted compute base safe from the rest of the components in the system.

Protecting against hardware threats is not easy. Some organizations closely audit their supply chains to ensure the provenance of firmware and devices in their systems, and operate their servers in tightly controlled physical environments. For cloud environments or remote locations, this may not be an option. In those cases, minimizing the trust perimeter to a single component may be the best option to reduce the threat of hardware vulnerabilities and protect sensitive data in-use.