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ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

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Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#71

Post by rurban »

spockz wrote: post #2

According to their blog post[1], there is little you can do against this. Running different applications on different cpus help against them reading each other’s data but an rogue process can still read data from the “super ordinated kernel” or hypervisor.

Of course you can fix it. I fixed it in Dec 2018 for most such attacks in my safelibc memset_s implementation, but nobody wanted to use it, because securely purging the buffers with secrets via mfence was deemed to slow. So everybody can read your secrets via sidechannel attacks. These tiny MDS buffers need to be purged with verw or l1d_flush followed by an lfence. This needs to be added to memset and memset_s variants. This is much faster. But it will not happen, libc maintainers notoriously don't care, even crypto maintainers not. Only Linux does.

https://software.intel.com/security-software-guidance/softwa...

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#72

Post by fwip »

outworlder wrote: post #68
lawnchair_larry wrote: post #51

Earlier quoted context omitted.

This is a common pattern for new bug classes. Nobody thought to look at this, and when they did, the rabbit hole went deep. We likely haven’t seen the bottom. AMD are not better. They’re probably worse. They’ll be looked at when the Intel tree stops bearing fruit. But finding an Intel bug is higher impact, so that’s what researchers want to look at.

> AMD are not better. They’re probably worse. This argument makes zero sense and fails real world inspection. You see, researchers did publish the fact that it affected AMD on Spectre. For this vulnerability, they were unable to reproduce the bug on AMD (their words). Which means that they tried.

Intel and AMD don't have to share the same bugs for AMD to be worse.

Consider you've got two sets of vulnerabilities: [1, 2, 3] and [2, 4, 5, 6, 7, 8].

If I label set 1 Intel, and set 2 AMD, then you can see how doing your research on Intel first will make it seem like Intel has 3x the vulnerabilities as AMD - even though it actually has half.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#73

Post by pcwalton »

faissaloo wrote: post #18
jamiek88 wrote: post #5

9% hit potentially on performance in data center. Add in all the Spectre and meltdown mitigations and we have potentially lost nearly two generations of Intel performance increases. Just shows the hoops and tricks needed to keep making, on paper, faster processors year on year but without node shrinks to give headroom. 14nm++++ is played out.

I wonder at what point the hardware fix for these issues stop becoming worthwhile and if we'll see a resurgence of processors without speculative execution or any of these other speed ups.

You can kiss any semblance of reasonable performance goodbye if you eliminate "speculative execution". Pipelining is the most basic tool in the toolbox. Even microcontrollers do it.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#74

Post by monocasa »

daeken wrote: post #12
penagwin wrote: post #8

Earlier quoted context omitted.

Not arguing just asking, but how has Pandora's box been opened with the discloser of Spectre and Meltdown? We've had security researchers discovering and reporting vulnerabilities since there were computers as far as I know? I do agree that this won't end soon though. It appears to me that many of the methods CPU's use for better performance are fundamentally flawed in their security, and it's not like we can expect…

Before Spectre and Meltdown were disclosed publicly, very very few security researchers were looking at the CPU level, beyond things like attacks against hardware virtualization functionality, TrustZone and friends, ME, etc. Those bugs had existed for ages and could've been found through thorough examination of the processor manuals, but nobody had really looked too hard there. These new bugs were found independently…

But like, those bugs were there. They might have been being exploited and not been caught.

Your argument sounds like an argument against responsible disclosure totally.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#75

Post by flattone »

daeken wrote: post #12
penagwin wrote: post #8

Earlier quoted context omitted.

Not arguing just asking, but how has Pandora's box been opened with the discloser of Spectre and Meltdown? We've had security researchers discovering and reporting vulnerabilities since there were computers as far as I know? I do agree that this won't end soon though. It appears to me that many of the methods CPU's use for better performance are fundamentally flawed in their security, and it's not like we can expect…

Before Spectre and Meltdown were disclosed publicly, very very few security researchers were looking at the CPU level, beyond things like attacks against hardware virtualization functionality, TrustZone and friends, ME, etc. Those bugs had existed for ages and could've been found through thorough examination of the processor manuals, but nobody had really looked too hard there. These new bugs were found independently…

this person seems to think that security researchers are the only people looking for vulnerabilities when in fact the people who stand to have significant profits are apt where the vulnerabilities were probably known long before researchers found them

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#76

Post by Fej »

What is the recommended course of action? Stop buying Intel products, and devices which contain them?

What about devices with older processors? I'm still running a Sandy Bridge rig and it works fine, except for the side channel vulnerablities. It's probably not going to be patched. I also have a cheaper computer with a Skylake processor, which is newer yet still vulnerable!

It's only a matter of time until something really nasty comes along, making all these PCs dangerous to use. What then? Lawsuits?

My questions are only partially rhetorical.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#77

Post by starshadowx2 »

monocasa wrote: post #74
daeken wrote: post #12

Earlier quoted context omitted.

Before Spectre and Meltdown were disclosed publicly, very very few security researchers were looking at the CPU level, beyond things like attacks against hardware virtualization functionality, TrustZone and friends, ME, etc. Those bugs had existed for ages and could've been found through thorough examination of the processor manuals, but nobody had really looked too hard there. These new bugs were found independently…

But like, those bugs were there. They might have been being exploited and not been caught. Your argument sounds like an argument against responsible disclosure totally.

Opening Pandora's Box is a good thing. It gets the issues out in the air and visible so you know what more to look out for and what needs to be fixed.

Don't forget that Hope was also released when the box was opened.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#78

Post by [deleted] »

daeken wrote: post #12
penagwin wrote: post #8

Earlier quoted context omitted.

Not arguing just asking, but how has Pandora's box been opened with the discloser of Spectre and Meltdown? We've had security researchers discovering and reporting vulnerabilities since there were computers as far as I know? I do agree that this won't end soon though. It appears to me that many of the methods CPU's use for better performance are fundamentally flawed in their security, and it's not like we can expect…

Before Spectre and Meltdown were disclosed publicly, very very few security researchers were looking at the CPU level, beyond things like attacks against hardware virtualization functionality, TrustZone and friends, ME, etc. Those bugs had existed for ages and could've been found through thorough examination of the processor manuals, but nobody had really looked too hard there. These new bugs were found independently…

[deleted]

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#79

Post by jcims »

monocasa wrote: post #74
daeken wrote: post #12

Earlier quoted context omitted.

Before Spectre and Meltdown were disclosed publicly, very very few security researchers were looking at the CPU level, beyond things like attacks against hardware virtualization functionality, TrustZone and friends, ME, etc. Those bugs had existed for ages and could've been found through thorough examination of the processor manuals, but nobody had really looked too hard there. These new bugs were found independently…

But like, those bugs were there. They might have been being exploited and not been caught. Your argument sounds like an argument against responsible disclosure totally.

I'm not reading anything against responsible disclosure in deaken's comments. How are you getting that?

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#80

Post by jcims »

ficklepickle wrote: post #53
jcoffland wrote: post #36

Earlier quoted context omitted.

It should read: > ...said it works “just like” in PCs The number of mistakes in the Techcrunch article is atrocious.

I found two and emailed the author. It's my sad little hobby. He replied promptly and they all should be fixed now. In fact, he found a third that I missed. Keep in mind, this article was posted at 3am pacific, 6am eastern. Assuming the author is in North America, he was probably under a deadline and rather tired. I have found similar typos from prominent writers. Sometimes they email me back, which I appreciate. I f…

Your 'sad little hobby' is directly addressing one of the biggest cultural problems we face today. For some reason I never thought to approach it that way, I may pick it up myself if you don't mind the company.
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