Tuesday, April 6th 2021
AMD Ryzen 5000 Series CPUs with Zen 3 Cores Could be Vulnerable to Spectre-Like Exploit
AMD Ryzen 5000 series of processors feature the new Zen 3 core design, which uses many techniques to deliver the best possible performance. One of those techniques is called Predictive Store Forwarding (PSF). According to AMD, "PSF is a hardware-based micro-architectural optimization designed to improve the performance of code execution by predicting dependencies between loads and stores." That means that PSF is another "prediction" feature put in a microprocessor that could be exploited. Just like Spectre, the feature could be exploited and it could result in a vulnerability in the new processors. Speculative execution has been a part of much bigger problems in CPU microarchitecture design, showing that each design choice has its flaws.
AMD's CPU architects have discovered that the software that relies upon isolation aka "sandboxing", is highly at risk. PSF predictions can sometimes miss, and it is exactly these applications that are at risk. It is reported that a mispredicted dependency between load and store can lead to a vulnerability similar to Spectre v4. So what a solution to it would be? You could simply turn it off and be safe. Phoronix conducted a suite of tests on Linux and concluded that turning the feature off is taking between half a percent to one percent hit, which is very low. You can see more of that testing here, and read AMD's whitepaper describing PSF.
Source:
AMD Blog
AMD's CPU architects have discovered that the software that relies upon isolation aka "sandboxing", is highly at risk. PSF predictions can sometimes miss, and it is exactly these applications that are at risk. It is reported that a mispredicted dependency between load and store can lead to a vulnerability similar to Spectre v4. So what a solution to it would be? You could simply turn it off and be safe. Phoronix conducted a suite of tests on Linux and concluded that turning the feature off is taking between half a percent to one percent hit, which is very low. You can see more of that testing here, and read AMD's whitepaper describing PSF.
65 Comments on AMD Ryzen 5000 Series CPUs with Zen 3 Cores Could be Vulnerable to Spectre-Like Exploit
Intel actually pays people for finding them. "Intel’s bug bounty awards range from $500 up to $100,000."
AMD had plenty of vulnerabilies, even tho they don't pay people for finding them. Meaning, very few people will spend time trying to find them. Logic 101.
It's sad that AMD does not pay people for finding bugs, when tons of big tech companies do; www.guru99.com/bug-bounty-programs.html
Lot of anti-AMD comments for something that doesn't have an exploit yet. Mind you the performance difference is near nothing anyways so it wouldn't mean much to begin with. I'm guessing as usual, the typical suspects rush to the comments without reading.
The only reason things aren't as dire as they could have been is that COVID-19 has reduced the server loads these last 13 months. Under normal circumstances, the loss of performance from applying mitigation steps and patches would have f***ed us over, hard, and expensively.
Yeah, nothing to fret about. Just turn it off and move on.
1.) ALL CPUs have bugs, and some can be exploited... Shock, horror...
2.) Intel have their own engineers looking at AMD CPUS all day long, looking for some dirt that they can use to create a fake security research company, setup a flashy website with fancy graphics, complete with fancy names for the exploits, and drum up a lynch mob to tank AMD shares. Think it don't happen? yeah right...
3.) Ever heard of ransomware? Maybe there is no money in finding an exploit... yeah...
4.) ALL future CPUs will have bugs, and will be exploited...
There are so many wrongs in your logic and others already mentioned a few. Intel could be paying not only so it can improve it's CPUs, but also to try to silence people as long as necessary to create hardware fixes for future revisions. Also no one should assume that Intel is not paying for vulnerabilities on Ryzen CPUs. Intel was really hit hard, for a period of time, with all those security holes on it's CPUs monopolizing the news. And while we can't say that they have payed people to create fictional problems on AMD CPUs (do you remember that Israeli firm? ), they probably have payed to find vulnerabilities in a competing product that is eating from their market share. Not to mention that huge companies, like Google, or Amazon, or Microsoft who use AMD's Epyc processors, probably keep looking for vulnerabilities themselves, or pay others to do so. They have plenty of money to spent.
Your logic reminds me of "Linux is as bad in security as Windows, we only don't see security problems on Linux because of it's small market share".
Any company making tech products should take any vulnerability seriously, but it's the risk and consequences which should dictate which customers should take action. The Spectre class bugs (and really Meltdown too) should be considered nearly "theoretical" problems. While you can certainly reproduce them in controlled environments, any successful exploit would still require access to running custom software locally, and usually a lot of time to extract useful information. Many of these known exploits are able to extract privileged data at bytes per second or kB per second, while it's burning your CPU with load for weeks or months to find something valuable. For desktop users, these exploits are pretty much irrelevant; if I'm able to run my program on your machine, then I already have access to everything in your user space, so I probably already own all your files anyway.
The Spectre class of bugs is only really scary for cloud providers, where there is a theoretical possibility that one VM can steal data from another, bypassing all layers of security. But I want to stress, this is practically theoretical, executing a such attack and gaining substantial useful and intact information is going to be hard, especially since data will be moved around by the time someone can dump enough of it. But those who are putting sensitive information or critical systems in the public cloud are pretty "stupid" anyways.
The real impact of Spectre is the cost of mitigations, while it's negligible for most users, it can be significant for very specific server loads or some edge cases.
Meanwhile, as normal desktop users, there are many more serious security issues to worry about, including your crappy router/access point, all the IoT devices you carelessly connect, and keeping your systems up to date and passwords managed.
All this isn't even because of a CVE-assigned vulnerability. All this because of a goddamn whitepaper published by AMD, *speculating* on potential risks. Yeah no shit, it's speculative execution. And now all the trolls come out of the woodwork either defending their double standards for almighty AMD or thinking the tables have turned for their darling Intel.
Holy hell, some of the justifications on here are hokey as shit. Intel pays people to find bugs, but it's unreasonable to impose an NDA that gives them reasonable time to evaluate and solve it, and that constitutes a cover-up? What, did Intel pay dirty money to commission AMD to make this AMD whitepaper too? Jumping jack christ, some of the hypocrisy could be painted bright yellow and illuminated with floodlights and some of you would miss it.
AMD's current recommendation at the bottom of the whitepaper that is the friggin subject of this article: leave it on. So 5000 owners leave it on and go about your day. If this ever changes, and AMD makes a recommendation like Intel did to turn it off, then it would be wise to reconsider.
They are still issues.
Surely that's obvious? Is that really what you're asking?
The mitigation: perhapsThe Spectre class of bugs don't really allow people to hack your computer. They need to execute the attack locally on your computer, so essentially hack it first.