Massive security hole in CPU's incoming?Official Meltdown/Spectre Discussion Thread

[Hitman928]

I'm not engineer and don't know how critical this Ring vulnerability is, but it sounds like it only affect Intel because of Ring. Is it fixable via bios update? Don't tell me this would lead to some other bit of performance lost......

They couldn't 'fix' this with a BIOS update. They may be able to mitigate it to some degree, but it will have some sort of performance penalty associated with it.

 

[DrMrLordX]

The exploit relies on the ring bus protocol itself. Can they even modify that behavior with microcode updates?

 

[LP-ZX100C]

Another one

https://twitter.com/x/status/1373059799307390981

 

[moinmoin]

Looks like it uses some instruction code previously used by AMD's 3DNow! extension. I guess having some software already use an instruction Intel never acknowledged makes for a good camouflage for new instructions of this kind. Security by obscurity at its finest...

 

[Panino Manino]

Is this the fabled "backdoor"?

 

[Kenmitch]

Clearly Intel is the winner in un-security.

 

[chris george]

https://pythonsweetness.tumblr.com%2Fpost%2F169166980422

Quoted from a reddit thread.

This could be big. Many a sysadmin might have sleepless nights soon enough.

EDIT: Since news and clarification arrived, I'll add it here.
Official website with details: https://meltdownattack.com
TL;DR
There are two attacks exploiting similar ideas, called Meltdown and Spectre.

Meltdown affects all Intel CPU's going back a decade, and some select ARM CPU's. It is the more pressing issue of the two, and potentially compromises systems completely due to its power. Patches already went out on both Linux and Windows to mitigate it. Performance hit depends on workload, gaming not noticeably affected.

Spectre affects all CPU's aside from specialized microcontrollers and other low powered devices. It is harder to exploit but also harder to fix. The full consequences and effects of it are still unknown, but all major tech companies are taking steps to research and mitigate it.

Intel Press Release: https://newsroom.intel.com/news/intel-responds-to-security-research-findings/

AMD Press Release: https://www.amd.com/en/corporate/speculative-execution

Apple Press Release: https://support.apple.com/en-us/HT208394

ARM Press Release: https://developer.arm.com/support/security-update



Updated title of the thread to include other CPU companies.


esquared
Anandtech Forum Director

good info

 

[UsandThem]

good info

It really is, isn't it?

 

[Racan]

Oh boy, here we go again...

A new Spectre vulnerability is costly to patch but nearly impossible to exploit | TechSpot

 

[ondma]

It should be pointed out, this vulnerability affect *both* AMD (since 2017) and Intel (since 2011).

 

[Hitman928]

I don't have time to go through the paper right now but if the following from the article is true:

Fortunately, the exploitation of micro-op cache vulnerabilities is believed to require a high level of access to the target system, which standard security systems can prevent.

Then it's basically much ado about nothing, more academic interest than a real world threat.

 

[moinmoin]

I don't have time to go through the paper right now but if the following from the article is true:

Then it's basically much ado about nothing, more academic interest than a real world threat.

There is an update to the article stating:

The University of Virginia reached out to us to emphasize that the vulnerabilities are exploitable and should be mitigated against, even if the risk posed isn’t imminent. The researchers intend to collaborate with AMD and Intel and the wider cybersecurity community to overcome the "significant challenges" relating to the performance penalties of the mitigations.

In general it's always a good idea to mitigate potential problems since while they may be hard to exploit now that's rather likely to change in the future.

From the news post by the university:

The new Spectre variants Venkat’s team discovered even break the context-sensitive fencing mechanism outlined in Venkat’s award-winning paper.

Defenseless: UVA Engineering Computer Scientists Discover Vulnerability Affecting Computers Globally

Editor's Note, May 5, 2021: This story has been updated.

engineering.virginia.edu

Direct link to the paper: https://www.cs.virginia.edu/~av6ds/papers/isca2021a.pdf

 

[Hitman928]

There is an update to the article stating:


In general it's always a good idea to mitigate potential problems since while they may be hard to exploit now that's rather likely to change in the future.

From the news post by the university:

Defenseless: UVA Engineering Computer Scientists Discover Vulnerability Affecting Computers Globally

Editor's Note, May 5, 2021: This story has been updated.

engineering.virginia.edu

Direct link to the paper: https://www.cs.virginia.edu/~av6ds/papers/isca2021a.pdf

Mitigation is always going to be recommended by the security researchers, but in reality, I doubt it will be done if you have to have direct access / elevated permissions on the machine to begin with as suggested by the techspot article. Not if the performance penalties are as severe as they are suggesting.

 

[iamgenius]

New Spectre Flaws in Intel and AMD CPUs Affect Billions of Computers

Researchers have found a new variant of the Spectre vulnerability that bypasses all current protections built into Intel and AMD processors.

thehackernews.com

You must add personal commentary to your post in the CPU forum.
No dropping of links or video without comment.


esquared
Anandtech Forum Director

 

[Hitman928]

New Spectre Flaws in Intel and AMD CPUs Affect Billions of Computers

Researchers have found a new variant of the Spectre vulnerability that bypasses all current protections built into Intel and AMD processors.

thehackernews.com

This is the same vulnerability that @Racan posted about 3 days ago that we've been discussing. . .

 

[iamgenius]

This is the same vulnerability that @Racan posted about 3 days ago that we've been discussing. . .

Oh sorry, I thought it is a different one.

 

[Panino Manino]

Your CPU May Have Slowed Down on Wednesday

The death of hardware store optimization.

travisdowns.github.io

I really hope that after all this when the time comes to upgrade the systems at least some will change to AMD.

 

[DrMrLordX]

Wow IceLake got hammered in the L3 region. Not that it translates to absolute performance but still. Ouch! I wonder if TigerLake got the same microcode update? And Rocket Lake?

edit: it does! It affects IceLake-SP too! Oh dear.

Intel-Linux-Processor-Microcode-Data-Files/releasenote.md at main · intel/Intel-Linux-Processor-Microcode-Data-Files

Contribute to intel/Intel-Linux-Processor-Microcode-Data-Files development by creating an account on GitHub.

github.com

 

[beginner99]

Your CPU May Have Slowed Down on Wednesday

The death of hardware store optimization.

travisdowns.github.io

I really hope that after all this when the time comes to upgrade the systems at least some will change to AMD.

For cluelees people like me, what are the implications of disabling this optimization? like in the real world and not a synthetic benchmark?

 

[AdamK47]

Your CPU May Have Slowed Down on Wednesday

The death of hardware store optimization.

travisdowns.github.io

I really hope that after all this when the time comes to upgrade the systems at least some will change to AMD.

Linux updates. Irrelevant to most.

 

[moinmoin]

Linux updates. Irrelevant to most.

That's wrong. Linux distributions updating microcode is easier to follow and more transparent than under other OSes like Windows. But said microcode is independent from the OS and distributed as part of updates under all OSes.

 

[AdamK47]

That's wrong. Linux distributions updating microcode is easier to follow and more transparent than under other OSes like Windows. But said microcode is independent from the OS and distributed as part of updates under all OSes.

Show me the impact to Windows users.

 

[jpiniero]

Show me the impact to Windows users.

You'd have to benchmark it yourself with the microcode difference.

 

[DrMrLordX]

Show me the impact to Windows users.

Sounds like something suitable for @borandi or Andrei.

 

[Hitman928]

Somewhat of a vulnerability. Malware can tell if it is put into a sandbox environment on Intel CPUs which would allow it to stop executing or alter behavior, making it harder for researchers to figure out what the malware does.

Hackers abuse single bit change in Intel CPU register to evade detection

Palo Alto Networks discovers that Trap Flag is being abused to notify malware it is being analyzed

www.itpro.co.uk