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Re:Reading privileged memory with a side-channel by snowwrestler on Wednesday January 03, 2018 @11:30PM (#16068049)
The irony here is that a good ol' dedicated hardware web server is far less susceptible to Meltdown or Spectre than Google Cloud, because only your code is running on the CPUs.

I predict tonight's disclosures will lead to an uptick in interest in running websites on dedicated hardware, like we did back at the turn of the century.

Re:Reading privileged memory with a side-channel by tanilama on Wednesday January 03, 2018 @11:57PM (#16068155)
> Spectre

Spectre doesn't really care if it is cloud or bare metal. They are equally vulnerable unless disconnected from internet.

Re:Reading privileged memory with a side-channel by snowwrestler on Thursday January 04, 2018 @01:07AM (#16068389)
To get you with Spectre, the attacker must be able to run code on your CPU.

This affects browsers with Javascript enabled because your Javascript engine runs foreign code on the CPU. The bad guy puts nasty code in a page, you visit the page, the code executes on your machine--boom.

And it affects public cloud web servers because multiple cloud servers (virtual machines) run on one CPU. So some attacker might be able to jump out of their VM and read your VM's memory.

BUT, on a dedicated hardware web server, there shouldn't be any foreign code running--no foreign VMs, and no browser.

Re:Reading privileged memory with a side-channel by user5994461 on Thursday January 04, 2018 @02:48AM (#16068673)
There are many dedicated servers that are shared across users or clients and were expected to be isolated.

Any user who has access to a system (developers or support or sysadmin) has the ability to read arbitrary memory. The vulnerability can probably be leveraged to privilege escalation or bypass the isolation.

Re:Reading privileged memory with a side-channel by tanilama on Thursday January 04, 2018 @06:11AM (#16069428)
Spectre doesn't let u do cross VM memory reading, Meltdown does, AFAIK. If you want to read other VMs memory, u need to RUN in those VMs yourself and within the right process.

So cloud instance and bare metal ones are equally vulnerable under Spectre: as long as they can transfer their malicious code to your VMs and runs it. Can't really see how bare metal servers mitigate this problem.

Re:Reading privileged memory with a side-channel by Godel_unicode on Thursday January 04, 2018 @12:23AM (#16068251)
Pretty hard to have a neighbor vm execute Spectre on your same physical server if you have dedicated hardware.

Add in that Spectre specifically is a js bug so in order to be vulnerable your server would need to execute untrusted JavaScript and I think we can assume the threat surface of this specific bug is smaller outside the cloud...

Re:Reading privileged memory with a side-channel by spotman on Thursday January 04, 2018 @12:49AM (#16068339)
Pretty sure that its not limited to js:

https://gist.github.com/ErikAugust/724d4a969fb2c6ae1bbd7b2a9...

Its a technique, not a flaw in js, from my understanding

Re:Reading privileged memory with a side-channel by Godel_unicode on Thursday January 04, 2018 @12:53AM (#16068350)
This PoC is implemented in js, but my point stands regardless of the language used. It requires code executing on the same physical server as your app in order to be an issue for you. Similar to a hypervisor escape (since we're being pedantic yes, I understand this is not a hypervisor escape), the evil neighbor surface is not present if you have no neighbors.
Re:Reading privileged memory with a side-channel by cthalupa on Thursday January 04, 2018 @12:48AM (#16068334)
I don't think you understand the bug here.

1) https://spectreattack.com/: "Spectre tricks other applications into accessing arbitrary locations in their memory. " Spectre does not let you execute code in another guest

2) Spectre is not javascript specific. I am not sure why you think it is, beyond the fact a PoC was written in js

Re:Reading privileged memory with a side-channel by Godel_unicode on Thursday January 04, 2018 @12:57AM (#16068362)
I don't think you understand my point. You should reread my post, especially the first sentence. It's first and alone for a reason; not sharing hardware is an effective mitigation against vulnerabilities in shared hardware.

Obviously it's not just a js bug, there are other PoCs in other languages.

I never said anything about executing code in another guest, not sure where you got that from.

Re:Reading privileged memory with a side-channel by cthalupa on Thursday January 04, 2018 @10:10AM (#16070830)
>Pretty hard to have a neighbor vm execute Spectre on your same physical server if you have dedicated hardware.

You have no reason to care about a neighbor VM executing Spectre on the same physical server, since they're only hurting themselves, not you.

>Add in that Spectre specifically is a js bug so in order to be vulnerable your server would need to execute untrusted JavaScript and I think we can assume the threat surface of this specific bug is smaller outside the cloud...

"Spectre specifically is a js bug"

Re:Reading privileged memory with a side-channel by TickleSteve on Thursday January 04, 2018 @08:45AM (#16070246)
Spectre is exploitable from processes, not just containers.... containers are equivalent to processes from it's point-of-view as the kernel is shared.

So... you may be able to go native to avoid having neighbours, but this does not prevent other processes exploiting your process. To do that you need to prevent any downloadable code from running.

This of course is possible and is the entire reason why the ARM document explains that most embedded systems are not affected due to the fact that they will not download and execute code (of any form).