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Operation Triangulation: What you get when attack iPhones of researchers

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Re: Operation Triangulation: What you get when attack iPhones of researchers

#361

Post by mike_hearn »

Veserv wrote: post #246
mike_hearn wrote: post #76

Earlier quoted context omitted.

I don't think hiring an ex-Apple dev would let you get the needed sbox unless they stole technical documentation as they left. So it either has to be stolen technical docs, or a feature that was put there specifically for their usage. The fact that the ranges didn't appear in the DeviceTree is indeed a bit suspicious, the fact that the description after being added is just 'DENY' is also suspicious. Why is it OK to d…

It should be very easy to add one without somebody noticing. This is the same Apple which shipped a version of macOS for months that added the ability to login to root with any password only a few years ago. Their review processes are so incompetent even one of the most security critical components, root login, let a totally basic “fail your security 101 class” bug through. It is absolutely inexcusable to have a proc…

Mistakes happen but Apple's reputation for strong security is well deserved. They invest heavily and the complexity of this exploit chain is evidence of that. Linux has had its fair share of trivial root login exploits that somehow got through code review.

Re: Operation Triangulation: What you get when attack iPhones of researchers

#362

Post by mike_hearn »

justinclift wrote: post #357
mike_hearn wrote: post #76

Earlier quoted context omitted.

I don't think hiring an ex-Apple dev would let you get the needed sbox unless they stole technical documentation as they left. So it either has to be stolen technical docs, or a feature that was put there specifically for their usage. The fact that the ranges didn't appear in the DeviceTree is indeed a bit suspicious, the fact that the description after being added is just 'DENY' is also suspicious. Why is it OK to d…

> I don't think hiring an ex-Apple dev would let you get the needed sbox That'd probably depend on which team the dev worked in. If they were in the right team, then it might.

What I mean is that (assuming the sbox values are actually random) you couldn't memorize it short of intensive study and practice of memory techniques. If the "sbox" is in reality some easily memorizable function then maybe, but even then, how many people can remember long hex values from their old jobs?

Re: Operation Triangulation: What you get when attack iPhones of researchers

#363

Post by adrian_b »

duskwuff wrote: post #325
smallnix wrote: post #289

Earlier quoted context omitted.

That does not explain the weird hashing.

As explained by marcan: it's not "hashing", it's an error-correcting code. Much more understandable in that light. https://social.treehouse.systems/@marcan/111655847458820583

That the secret registers are in fact cache test registers, as explained at that link, is a very plausible explanation for their existence.

Nevertheless, this does not explain at all the astonishing fact that they were mapped by default in the accessible memory space, unless listed and explicitly denied in the system configuration files.

No amount of incompetence seems enough to explain such a default policy, so the supposition of an intentional backdoor still seems more likely.

Re: Operation Triangulation: What you get when attack iPhones of researchers

#364

Post by computerfriend »

LargeTomato wrote: post #281
malaya_zemlya wrote: post #273

Earlier quoted context omitted.

>also is indicative of a massive organization with truly abysmal levels of internal siloing. Or a joint project between several organizations.

Or, like, they have a root kit and it works so why reinvent the wheel? They have an attack payload so why reinvent the wheel? Just plug and play all the packages you need until you can compromise your target device.

But there is a very good reason to reinvent the wheel here: to not burn more zero-days than you have to.

Re: Operation Triangulation: What you get when attack iPhones of researchers

#365

Post by mike_hearn »

supriyo-biswas wrote: post #333
mike_hearn wrote: post #43

That's pretty astonishing. The MMIO abuse implies either the attackers have truly phenomenal research capabilities, and/or that they hacked Apple and obtained internal hardware documentation (more likely). I was willing to believe that maybe it was just a massive NSA-scale research team up until the part with a custom hash function sbox. Apple appears to have known that the feature in question was dangerous and delib…

So much misinformation in this thread. It’s a Hamming ECC, as described here[1]. [1] https://social.treehouse.systems/@marcan/111655847458820583

Very interesting, thanks. Summarizing that thread:

- The "hash" is probably an error correcting code fed into GPU cache debug registers which will be stored in the cacheline itself, you're expected to compute the ECC because it's so low level. That is, the goal isn't to protect the DMA interface. (but this isn't 100% certain, it's just an educated guess)

- The "sbox" is similar to but not the same as a regular ECC as commonly used in hardware.

- Martin argues that the existence of such registers and the code table could have been guessed or brute forced, even though a compromise or info leak from Apple seems more likely. Or possibly even from the old PowerVR days. But if it's the NSA then who knows, maybe they are literally fuzzing hidden MMIO ranges to discover these interfaces.

- This is possible because the GPU has full DMA access without an IOMMU for performance reasons, so it's fertile ground for such exploits. Probably more will be discovered.

So that's all reassuring.

Re: Operation Triangulation: What you get when attack iPhones of researchers

#366

Post by mike_hearn »

LargeTomato wrote: post #281
malaya_zemlya wrote: post #273

Earlier quoted context omitted.

>also is indicative of a massive organization with truly abysmal levels of internal siloing. Or a joint project between several organizations.

Or, like, they have a root kit and it works so why reinvent the wheel? They have an attack payload so why reinvent the wheel? Just plug and play all the packages you need until you can compromise your target device.

The attack payload should not be so tied to an exact installation path that you can't just install it via a different exploit chain.

Re: Operation Triangulation: What you get when attack iPhones of researchers

#367

Post by _kbh_ »

cf1241290841 wrote: post #352
_kbh_ wrote: post #345

Earlier quoted context omitted.

> Decade old Backdoors no I really doubt it's a backdoor after reading the blog post and this thread chain from a prolific M1 MacBook hacker (macran) I think it was just an unused or very rarely used feature that was left enabled by accident. https://social.treehouse.systems/@marcan/111655847458820583 Some choice quotes. First, yeah, the dbgwrap stuff makes perfect sense. I knew about it for the main CPUs, makes perf…

>I really doubt it's a backdoor after reading the blog post and this thread chain from a prolific M1 MacBook hacker (macran) I think it was just an unused or very rarely used feature that was left enabled by accident. Why? Apple isnt exactly a small family business and this is quite the drastic "feature" to be left enabled by accident. How would one look from your perspective?

> Why? Apple isnt exactly a small family business and this is quite the drastic "feature" to be left enabled by accident.

Mistakes happen, maybe it's used in the manufacturing or fab phase to test something. Maybe it's used by the GPU firmware itself to perform some operations.

Maybe it was used by some older SoCs to do something and was just never removed.

Apple may not be a small family business but silly mistakes still happen all over the place in nearly every large system.

To quote another post by macran cause I feel like it's super relevant when trying to analyse how this kind of stuff comes about.

@nicolas17 @nil Correct. The question is, how many more of these fun bypasses are left undiscovered? The GPU is a huge amount of hardware and firmware.

Computers are so incredibly complicated now days that these kinds of hardware bugs are likely sitting around elsewhere as well, they don't come around that often because the amount of effort required to find them is likely a lot, which is likely only viable for a nation state actor.

Re: Operation Triangulation: What you get when attack iPhones of researchers

#368

Post by justinclift »

mike_hearn wrote: post #362
justinclift wrote: post #357

Earlier quoted context omitted.

> I don't think hiring an ex-Apple dev would let you get the needed sbox That'd probably depend on which team the dev worked in. If they were in the right team, then it might.

What I mean is that (assuming the sbox values are actually random) you couldn't memorize it short of intensive study and practice of memory techniques. If the "sbox" is in reality some easily memorizable function then maybe, but even then, how many people can remember long hex values from their old jobs?

Two points:

a) If a person is using those values daily for years (or even a couple of months), then it's very likely they'd have memorized them

b) Sometimes just knowing the concept exists for sure is good enough, as you can then go and brute force things until you've worked out the values

Re: Operation Triangulation: What you get when attack iPhones of researchers

#369

Post by codedokode »

supriyo-biswas wrote: post #333
mike_hearn wrote: post #43

That's pretty astonishing. The MMIO abuse implies either the attackers have truly phenomenal research capabilities, and/or that they hacked Apple and obtained internal hardware documentation (more likely). I was willing to believe that maybe it was just a massive NSA-scale research team up until the part with a custom hash function sbox. Apple appears to have known that the feature in question was dangerous and delib…

So much misinformation in this thread. It’s a Hamming ECC, as described here[1]. [1] https://social.treehouse.systems/@marcan/111655847458820583

Why do you need error-correction code for a debugging feature though? I would not protect debug registers with a hash.

Re: Operation Triangulation: What you get when attack iPhones of researchers

#370

Post by raverbashing »

mike_hearn wrote: post #362
justinclift wrote: post #357

Earlier quoted context omitted.

> I don't think hiring an ex-Apple dev would let you get the needed sbox That'd probably depend on which team the dev worked in. If they were in the right team, then it might.

What I mean is that (assuming the sbox values are actually random) you couldn't memorize it short of intensive study and practice of memory techniques. If the "sbox" is in reality some easily memorizable function then maybe, but even then, how many people can remember long hex values from their old jobs?

But having predictably generated sequence of numbers is what cryptographers prefer

https://en.wikipedia.org/wiki/Nothing-up-my-sleeve_number

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