Archive for January 3, 2018

Intel, AMD, ARM All Make Statements About Epic CPU Bug… Alongside New Details About The Bug

Posted in Commentary with tags , , on January 3, 2018 by itnerd

This morning it came to light that there was a memory access design flaw in Intel processors and fixing it could lead to a performance drop.

Security researchers have now shared details about two separate critical vulnerabilities impacting most Intel processors and some ARM processors. Called Meltdown and Spectre, which sound like the names of James Bond movies. But I digress. The vulnerabilities offer hackers access to data from the memory of running apps, providing passwords, emails, documents, photos, and more. In short, if you have bought a computer or smartphone since 1995, the pwnage is real for you but it is patchable. However, Spectre impacts all processors, including those from ARM and AMD, and while it is harder to exploit, there is no known fix. Fully addressing Spectre will require a re-architecture of how processors are designed. Google has also shared details on the exploits. Full research papers on Meltdown and Spectre are available here. Oh yeah, proof of concept exploits are in the wild as we speak. It’s not known if hackers have exploited Meltdown and Spectre. But if they haven’t, they will.

Late today Intel came out with a statement posted on its website, Intel says that it planned to disclose the vulnerability next week when additional software patches were available, but was forced to make a statement today due to “inaccurate media reports.” Whatever that means. Here’s part of the statement:

Intel and other technology companies have been made aware of new security research describing software analysis methods that, when used for malicious purposes, have the potential to improperly gather sensitive data from computing devices that are operating as designed. Intel believes these exploits do not have the potential to corrupt, modify or delete data.

Recent reports that these exploits are caused by a “bug” or a “flaw” and are unique to Intel products are incorrect. Based on the analysis to date, many types of computing devices — with many different vendors’ processors and operating systems — are susceptible to these exploits.

Interesting. A statement that’s designed to create plausible deniability and avoid a massive lawsuit. But wait, there’s more!

Intel has begun providing software and firmware updates to mitigate these exploits. Contrary to some reports, any performance impacts are workload-dependent, and, for the average computer user, should not be significant and will be mitigated over time.

That’s clearly designed to blunt any criticisms of the whatever patches are needed to fix this. Interestingly,  AMD came out with a statement that says this:

There is a lot of speculation today regarding a potential security issue related to modern microprocessors and speculative execution. As we typically do when a potential security issue is identified, AMD has been working across our ecosystem to evaluate and respond to the speculative execution attack identified by a security research team to ensure our users are protected.

To be clear, the security research team identified three variants targeting speculative execution. The threat and the response to the three variants differ by microprocessor company, and AMD is not susceptible to all three variants. Due to differences in AMD’s architecture, we believe there is a near zero risk to AMD processors at this time. We expect the security research to be published later today and will provide further updates at that time.

And ARM says this:

I can confirm that ARM have been working together with Intel and AMD to address a side-channel analysis method which exploits speculative execution techniques used in certain high-end processors, including some of our Cortex-A processors. This method requires malware running locally and could result in data being accessed from privileged memory. Please note our Cortex-M processors, which are pervasive in low-power, connected IoT devices, are not impacted.

We are in the process of informing our silicon partners and encouraging them to implement the software mitigations developed if their chips are impacted.

Sounds like of the three, ARM is the most honest. With AMD coming in a very close second. Intel strangely says nothing about reading kernel level data in their statement. You have to wonder why that is.


#Fail: Intel Chips Have Memory Access Design Flaw & The Fix Could Lead To A Performance Drop

Posted in Commentary with tags on January 3, 2018 by itnerd

This isn’t good. A serious design flaw and security vulnerability has been discovered in Intel’s CPUs that will require an update at the operating system level to fix, reports The Register:

Programmers are scrambling to overhaul the open-source Linux kernel’s virtual memory system. Meanwhile, Microsoft is expected to publicly introduce the necessary changes to its Windows operating system in an upcoming Patch Tuesday: these changes were seeded to beta testers running fast-ring Windows Insider builds in November and December.

So a fix is inbound. But the fix might be worse than the cure:

Crucially, these updates to both Linux and Windows will incur a performance hit on Intel products. The effects are still being benchmarked, however we’re looking at a ballpark figure of five to 30 per cent slow down, depending on the task and the processor model. More recent Intel chips have features – such as PCID – to reduce the performance hit. Your mileage may vary.

And for you Mac fans out there, you’re affected too. Not to mention quite a few other operating systems:
Similar operating systems, such as Apple’s 64-bit macOS, will also need to be updated – the flaw is in the Intel x86-64 hardware, and it appears a microcode update can’t address it. It has to be fixed in software at the OS level, or go buy a new processor without the design blunder.
Excellent. And by excellent I mean that this sucks. So, what is the actual vulnerability:

At best, the vulnerability could be leveraged by malware and hackers to more easily exploit other security bugs.

At worst, the hole could be abused by programs and logged-in users to read the contents of the kernel’s memory. Suffice to say, this is not great. The kernel’s memory space is hidden from user processes and programs because it may contain all sorts of secrets, such as passwords, login keys, files cached from disk, and so on. Imagine a piece of JavaScript running in a browser, or malicious software running on a shared public cloud server, able to sniff sensitive kernel-protected data.

Now the details are light and understandably so. Though one suspects that some evil doer is likely trying to figure out how to exploit this as we speak. What details do exist can be found at The Register story that I linked to. But this is a major screw up by Intel which is further underscored by the fact that AMD processors don’t have this issue. And seeing as it affects Intel processors that have been around for the last 10 year or so, this will likely be a significant story in 2018.

UPDATE: Mac users apparently don’t have to worry. If you’re running macOS 10.13.2, it was fixed in that version according to kernel expert Alex Ionescu:

And if you were worried about a performance drop because of this fix on your Mac:


Oh yeah. Proof of concept exploit code now exists, which is bad of course: