One good piece of news around Meltdown and Spectre is that security researchers aren’t seeing a ton of attacks stemming from these chip vulnerabilities. According to eWeek, security testing firm AV-Test reported on Feb. 1 seeing 139 malware samples—a very small number—related to both chip flaws, which were initially disclosed on Jan. 3. A McAfee security expert reported seeing more than 400 malware samples related to Meltdown and Spectre. For context, though, Avast sees tens of thousands of new malicious files every day, according to the eWeek article.
Still, if you design embedded devices and rely on secure microcontrollers to protect digital assets and intellectual property (IP), you might be concerned about these major security flaws. Well, if you are using Maxim DeepCover® secure microcontrollers, you have no reason for worry. Our secure microcontrollers based on Arm® Cortex®-M and ARM926™processors, our USIP PRO secure microcontrollers based on MIPS processors and, outside of our DeepCover portfolio, our MAXQ family of RISC microcontrollers are all unaffected by Meltdown and Spectre. For a look at how these chips have remained safe from these architectural flaws, let’s take a closer look at how both vulnerabilities work.
Meltdown and Spectre potentially expose critical information stored deep inside computer and embedded systems. This information includes passwords, proprietary data, and encrypted communications. Both have tapped into a vulnerability in the process of speculative execution, which computers use to decide their next course of action when encountering a test condition (“If x situation occurs, then do this; otherwise, do that.”). In this process, the computer speculatively executes the code that it deems most likely to run when confronted with a conditional test, speeding up computer processing time. Most of the time, its speculation is correct. In another move to optimize performance, chips have been designed with the assumption that this speculation process happens without visibility to any outside observers. However, attackers have found ways to see what happens within the speculative window and in so doing, they’ve been able to manipulate the system. An attacker can, for instance,trigger certain code sequences that would otherwise not be executed to run speculatively, according to a Red Hat blog post.
Meltdown impacts only Intel processors. Here, attackers have identified a way to break through the barrier that stops applications from accessing arbitrary locations in kernel memory, the place where sensitive data in plain format can typically be found. Spectre affects Intel as well as AMD and Arm processors (including some Cortex-A and Cortex-R processors). As a result, mobile devices and many internet of things (IoT) products are impacted. Spectre tricks applications into accidentally disclosing information that would otherwise be protected. TechCrunch reports that Meltdown can be thwarted via kernel page table isolation (essentially a stronger wall around the kernel), while with Spectre, “The fact is that the practice that leads to this attack being possible is so hard-wired into processors that the researchers couldn’t find any way to totally avoid it.”
Chipmakers, browser makers, and operating system developers have been issuing patches and other updates to mitigate speculative side-channel attacks. Notes TechCrunch, “A more permanent fix will require significant changes across the board—the circuit board, that is. Basic architecture choices that have been baked into our devices for years, even decades, will have to be rethought. It won’t be easy, and it won’t be fun.”
For Arm, only some Cortex-A and Cortex-R processors are affected by Spectre. That’s why the Cortex-M and ARM926 processors on which many of Maxim’s secure microcontrollers are based are not impacted. The same goes for our MAXQ and USIP products, as they also do not utilize speculative execution. Built with advanced cryptography and physical security, Maxim’s secure microcontrollers can provide strong protection from side-channel attacks, physical tampering, and reverse engineering.