Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
×
AMD Encryption Security

Researchers Crack Open AMD's Server VM Encryption (theregister.co.uk) 50

Shaun Nichols, reporting for The Register: A group of German researchers have devised a method to thwart the VM security in AMD's server chips. Dubbed SEVered (PDF), the attack would potentially allow an attacker, or malicious admin who had access to the hypervisor, the ability to bypass AMD's Secure Encrypted Virtualization (SEV) protections.

The problem, say Fraunhofer AISEC researchers Mathias Morbitzer, Manuel Huber, Julian Horsch and Sascha Wessel, is that SEV, which is designed to isolate VMs from the prying eyes of the hypervisor, doesn't fully isolate and encrypt the VM data within the physical memory itself.

This discussion has been archived. No new comments can be posted.

Researchers Crack Open AMD's Server VM Encryption

Comments Filter:
  • "malicious admin" (Score:4, Insightful)

    by Joffy ( 905928 ) on Friday May 25, 2018 @04:17PM (#56675430)
    I feel like some of these stories are like Bob's Home Security fails to protect you if your wife is a serial killer.
    • Re: (Score:3, Interesting)

      by Anonymous Coward

      Hey, Intel paid a lot of shekels for this very valuable research!

    • by vux984 ( 928602 ) on Friday May 25, 2018 @04:45PM (#56675600)

      "I feel like some of these stories are like Bob's Home Security fails to protect you if your wife is a serial killer."

      To an extent they are, but if you are using cloud providers, the other tennants, and the monkeys at the cloud provider itself should all be considered potentially hostile.

      And even within companies there is this (legitimate) concept that everyone in IT shouldn't hold the keys to payroll, finance, HR, and the R&D trade secretes... so there are lots scenarios where the people administering the systems, the servers, the cloud fabric etc, shouldn't be able to get access to the contents of the virtual machines.

      • Re: (Score:2, Interesting)

        by Anonymous Coward

        The old adage applies regardless: "He who has physical access, owns the data."

        It doesn't matter what it's running. If they have physical access, or local admin access, they own the data. All permissions derive from the admin account that set the system up in the first place. Trying to protect the system from the person who set it up / is responsible for maintaining it, is a fool's errand.

        The only reason we are having this discussion, is because everyone is too busy trying to save money by outsourcing the co

      • by Anonymous Coward

        but if you are using cloud providers, the other tennants, and the monkeys at the cloud provider itself should all be considered potentially hostile

        Um, yeah, but you considered them potentially hostile anyway. Nothing has changed. Except that maybe some snakeoil salesperson said that AMD's fancy new whatever would make it so that you could stop doing that, but you knew he was definitely lying, because it's impossible/impractical to hide software from the hardware it's running on.

        there are lots scenarios wher

    • The entire point of SEV (and Intel's SGX) is to protect the code against a malicious hypervisor. AMD tries to make a dubious distinction between a 'malicious' hypervisor and a 'compromised' hypervisor. Apparently they believe that if an attacker is able to run arbitrary code in the hypervisor, they are less of a threat than if they installed the same malicious code early on.

      That said, this is not news. There was a paper published at VEE a year ago (by the same researchers) showing how broken SEV is. Pa

  • Wait a minute... (Score:4, Insightful)

    by Narcocide ( 102829 ) on Friday May 25, 2018 @04:25PM (#56675484) Homepage

    If you have access to the hypervisor you already have full control over the guests even without this "exploit." Why is this considered a big deal exactly?

    • by Anonymous Coward

      Hush you. Intel just got hit with a bunch of new bad bugs, you're ruining the distractive narrative! We're all supposed to look at AMD now.

      • Is Intel vs. AMD part of the Marvel Universe yet? Because I have no problem ignoring all the superhero shit, and tis seems like the same kind of fanboy shit. Marvel! No, DC! No Intel! No no no! AMD!

        A bunch of comic book crap.

    • Consider it an incentive to not skimp on hypervisor programming.

      The problem, say Fraunhofer AISEC researchers Mathias Morbitzer, Manuel Huber, Julian Horsch and Sascha Wessel, is that SEV, which is designed to isolate VMs from the prying eyes of the hypervisor, doesn't fully isolate and encrypt the VM data within the physical memory itself.

      I wonder if that's because doing so would incur too much of a performance penalty?

      • by flux ( 5274 )

        The article ends with

        > "A low-cost efficient solution could be to securely combine the hash of the pageâ(TM)s content with the guest-assigned GPA."

    • by gweihir ( 88907 )

      Because people are stupid.

    • As I said above, because the entire point of SEV is that a malicious hypervisor can't tamper with a VM running in an SEV partition. Memory is encrypted, register contents are encrypted on context switch, and the VM can encrypt the contents of the disk and all network traffic itself. There are a number of flaws in the design that were pointed out to AMD (by this group of researchers, among others) before they shipped a product. AMD went ahead and shipped it anyway and, shockingly, it turns out that the at
  • by duke_cheetah2003 ( 862933 ) on Friday May 25, 2018 @07:17PM (#56676222) Homepage

    All modern PC's were never designed with the thought in mind: There will be millions of attacks against this to try and break in.

    We just didn't think about that when we designed this stuff, which was before the internet really took off. Of course it's all insecure and broken, it wasn't designed to be hardened against the countless ways security researchers are finding into these designs.

    When the "forces that be" decide to scrap everything we've created upto now, and start anew, with a security focus right at the starting line, then we'd get some hardware and software platforms that're truly hardened against any attack.

    Bandaids over the x86 paradigm? Waste of time. It's never going to be secure, not against everything everytime. It's just not designed to be secure, we didn't think it needed to be. We didn't think there'd be millions of malicious actors in the wild, with our computers all interconnected by the internet, so everything is exposed to everyone. We just didn't think that'd ever happen. It shows.

  • There is not really a way around this and there are numerous ways to bypass any protection mechanism. This is hardly news, except to the clueless that believe the marketing hype.

Research is what I'm doing when I don't know what I'm doing. -- Wernher von Braun

Working...