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Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

arxiv.org

21–30 of 66 posts

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#21

Earlier quoted context omitted.

> It's now beyond the ability of a rouge administrator or technician, requiring complex custom motherboards The end of the abstract explicitly refutes this. It is claiming that a software-only solution, using keys derived with this technique, can pretend to be a suitable target to migrate a secure VM to, which then allows the rogue admin to inspect or modify anything in the VM.

A bit unclear from the abstract whether the keys they learned how to derive (and the secret material they're derived from) are per individual chip or for all chips ever produced. If it's the former, that means the rogue admin still needs to electrically mess with the hardware once.

Though, that means you just need one modified motherboard.

Put each CPU in, extract the keys, deploy in a regular motherboard.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#22
post #2

With our findings, we prove that SEV cannot adequately protect confidential data in cloud environments from insider attackers, such as rouge administrators, on currently available CPUs. --- It is an interesting attack but is the above goal ever achievable? To protect against adversaries from the inside.

> rouge administrators It's not important but come on, if your field is cyber security at least make sure rogue is spelled correctly.

A rogue admin is acting alone, but rouge admins are part of the shadowy cabal and thus have access to many times more resources.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#23
post #2

With our findings, we prove that SEV cannot adequately protect confidential data in cloud environments from insider attackers, such as rouge administrators, on currently available CPUs. --- It is an interesting attack but is the above goal ever achievable? To protect against adversaries from the inside.

> rouge administrators It's not important but come on, if your field is cyber security at least make sure rogue is spelled correctly.

I would guess the GP is using French locales + autocompletion from a mobile device

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#24

Earlier quoted context omitted.

> It's now beyond the ability of a rouge administrator or technician, requiring complex custom motherboards The end of the abstract explicitly refutes this. It is claiming that a software-only solution, using keys derived with this technique, can pretend to be a suitable target to migrate a secure VM to, which then allows the rogue admin to inspect or modify anything in the VM.

A bit unclear from the abstract whether the keys they learned how to derive (and the secret material they're derived from) are per individual chip or for all chips ever produced. If it's the former, that means the rogue admin still needs to electrically mess with the hardware once.

The part about "without requiring physical access to the target host" would seem to imply that they only need access to a machine on their end for some attacks.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#25
post #9
post #2

With our findings, we prove that SEV cannot adequately protect confidential data in cloud environments from insider attackers, such as rouge administrators, on currently available CPUs. --- It is an interesting attack but is the above goal ever achievable? To protect against adversaries from the inside.

> It is an interesting attack but is the above goal ever achievable? To protect against adversaries from the inside. Achievable in any circumstances? No. Within a well-defined threat model, definitely.

Except that the threat model the crippled SEV defends against is the same one the SU command does, making it irrelevant.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#26
Similar attacks have already been demonstrated for other TEEs so nothing majorly new here (although the details are obviously different). The first work I'm aware of is an attack paper called CLKSCREW on ARM Trustzone. There were also some similar attacks published subsequently on SGX (Plundervolt). It's a hard problem to solve I think. One of the major dividing lines is whether the attack can be performed remotely (i.e. software only using OS power management APIs), or whether it requires physical access. The former obviously has more impact but most likely is much easier to mitigate than physical attacks.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#27
post #2

With our findings, we prove that SEV cannot adequately protect confidential data in cloud environments from insider attackers, such as rouge administrators, on currently available CPUs. --- It is an interesting attack but is the above goal ever achievable? To protect against adversaries from the inside.

> It is an interesting attack but is the above goal ever achievable? To protect against adversaries from the inside.

Yes. To expand: to a function on the CPU an administrator is just another user. The Operating System is responsible for managing those designations.

These trusted computing pieces across all kinds of CPUs are specifically aimed at protecting against people with host-root, so it would seem like it's a goal they've set for themselves and should be reasonably achievable.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#28

Earlier quoted context omitted.

> rouge administrators It's not important but come on, if your field is cyber security at least make sure rogue is spelled correctly.

A rogue admin is acting alone, but rouge admins are part of the shadowy cabal and thus have access to many times more resources.

They meet at the Mole in Rouge, blowing off the tension of secrecy by mansplaining each other Das Kapital.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#29

Earlier quoted context omitted.

> rouge administrators It's not important but come on, if your field is cyber security at least make sure rogue is spelled correctly.

Are you sure they aren't talking about these admins ? https://en.wikipedia.org/wiki/Wikipedia:Rouge_admin

One day, when I'm retired or homeless, I'd love to pull apart and try to understand the weird cultures of wikipedians.

Re: Fault Injection Attacks Against AMD's Secure Encrypted Virtualization

#30
post #23

Earlier quoted context omitted.

> rouge administrators It's not important but come on, if your field is cyber security at least make sure rogue is spelled correctly.

I would guess the GP is using French locales + autocompletion from a mobile device

I'm not talking about GP though, it's not important to make that mistake here. But the mistake is present in the paper.
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