Hacker News Reader

Comment by luma | Hacker News Reader

The remote access part is called AMT[1] and is part of the Intel vPro[2] feature set. It most certainly is not enabled in all modern Intel processors. Further, it requires a compatible processor, chipset, and BIOS for it to be enabled.

There is a common misunderstanding in these discussions that the ME features of the Intel processor (included in nearly all modern procs) allows for hardware level remote access, which isn't true.

[1] https://en.wikipedia.org/wiki/Intel_Active_Management_Techno... [2] https://en.wikipedia.org/wiki/Intel_vPro

View on HN

Yeah, right. I suppose we're just supposed to take their word for that. There's an enormous difference between the concepts of trusted and trustworthy. You're extremely naive or clearly never read anything Snowden released if you think 'trust us' is enough.

Are you suggesting Intel has implemented hidden backdoors into all of their systems?

Not OP but it could be very much possible and that's what OP is trying to say. Just taking it on Intel's word that they haven't done it is not the correct way to go. For the truly privacy minded, it's better to err on the side of caution.

Err on the side of caution in this sense would mean fabricating your own proc. Are you going to do that?

How do you know the fab you send your design to doesn't implement a backdoor? You have to have trust at SOME level.

How do you know the fab you send your design to doesn't implement a backdoor?

It really wouldn't be that hard to compare what you received from the foundry with the masks you sent them. There are services that decap ICs and attempt to reverse engineer them. Here's the first hit I found on Google: http://www.intelligservices.com/Services.htm

You wouldn't need the reverse engineering. All you would need to do is to compare that all the metal layers (and perhaps poly) match what you sent. That's an almost trivial comparison. The hard part of reverse engineering is in figuring out what the circuitry actually does, and you already know that, since it's your chip!

It could be possible for a fab to alter diffusion layers to change the functionality of a chip. That would be harder to detect by services such as the one I mentioned. But it would be very hard, very time consuming, to attempt to hack in a backdoor by only messing with base layers, rather than messing with metal or with poly (where changes are easily observed).

If there were to be a backdoor anywhere in a design, it would be in IP you used on your chip, that you got from either your foundry or from a 3rd party IP supplier. It would be easy enough to hide all kinds of stuff there.

That is exactly my point. If you don't trust Intel, then who are you suggesting should build your processor? Unless you are going to design and fabricate your entire system top to bottom, and have no other persons involved who could surreptitiously insert evil code, then you're going to have to accept some degree of trust in a 3rd party.

It's not just Intel you're trusting, it's the OEMs, who also have an EXTREMELY poor record. Just take a look at the ENORMOUS number up BMC and auto-update vulnerabilities. They really just either couldn't care less, or are deliberately making machines vulnerable. Things are being pushed into IME, that aren't optional, often aren't wanted by users (or snuck in there so they wouldn't know), don't all have to be there, can't be verifiably disabled or overriden by end users. Even if it weren't backdoored (unlikely), it presents an ENORMOUS attack surface at the very worst possible privilege level. Open source designs that are at least inspectable by researchers would be a start. But more importantly - allowing users to CHOOSE whether they want to override software (it IS after all software and not hardware). Why shouldn't we be permitted to run Libreboot etc on modern hardware and know that when we turn a machine off, that it's off, without unplugging network, power cables, batteries, etc?

AMT is full of holes too: http://people.kth.se/~maguire/DEGREE-PROJECT-REPORTS/100402-...

From what I've seen, Intel ME is the set of CPU features that supports applications such as Intel AMT. As Intel ME is built into all modern x86/x64 Intel CPUs, the possibility for exploiting Intel ME is still a security issue, even if some features aren't enabled by default.

To put it another way, what are some of the details that the author(s) of this article got wrong?

https://libreboot.org/faq/#intel

None, but you are taking away from it things that the article doesn't say. AMT is a subset of ME, it's not available on all procs, and even if it is available, it also requires the supporting chipset.

Nearly everyone reading this on a laptop/desktop system is doing so on an Intel processor. Go ahead and attempt to enable remote access without a supported proc/chipset/bios and then come back and complain about this unexpected remote access.

There is a lot of misunderstanding about this technology in the security world which strikes me odd because it's well-documented and readily available for your own testing.

True enough. But as I mentioned, I was rather terrified when I tried this on my thinkpad laptop. I'm sure many other business laptops have similar facilities (and yes, of course it is a feature to be able to manage a large fleet of machines, both work stations and servers).

As for trust, first, what we generally know is that any complex system is likely to have flaws. So any remote access system is likely a back door - intentionally or not. A physical off switch would be prudent (arguably switching off wireless network card and not connecting an ethernet cable is one option: but then your options are: no networking or possible vulnerability).

It's not as if any networked machine is "perfectly secure" - but it'd be nice to be able to set the scope of exposure even more easily, and granularly.

Second, one thing is trusting Intel to not intentionally install a back-door - keeping in mind that includes any "golden key" for updates. And not leaving any holes in the interface they expose (ie:getting the feature right). That in itself is a pretty high bar, imnho. But another thing is trusting Intel not to build in secret backdoors - that is; if they say, no, there's no IME in product X, then trust them on that. That is to me a much more trivial thing to trust. I know there will be bugs in the software and hardware, but I'm not all that afraid of maliciousness.

If I was working for a Chinese intelligence service the threat model might have been different.

In sum, given that there's bound to be bugs, and might be well-intentioned software upgrade support - I would prefer if it was easier to buy high-end parts without stuff like IME (this also applies to AMD btw) - or at least that it was easy to remove a jumper or toggle a dip switch to turn the stuff completely off.

[ed: finally re: server Vs laptop: there are some things that doesn't matter as much if it's exposed on a server: got my encrypted backups? Encrypted email? No problem. Got my secret key from my laptop? that is a problem]

Reply on news.ycombinator.com