Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Memory Integrity Enforcement

security.apple.com

Post reply on HN
Print view View original

201–210 of 259 posts

Re: Memory Integrity Enforcement

#201

Post by kevincox »

freakynit wrote: post #164
vayup wrote: post #160

> ...attackers must not be able to predict tag values that the system will choose. We address this issue by frequently re-seeding the underlying pseudo-random generator used to select new tags. This point could use more explanation. The fundamental problem here is the low entropy of the tags (only 4 bits). An attacker who randomly guesses the tags has 1/16 chance of success. That is not fixed by reseeding the PRNG. S…

Four bits provide too few possibilities. Since memory allocations happen millions of times per minute, the chance of collisions grows very quickly, even with periodic reseeding.

But you only get one try. 15/16 times you get a very visible failure.

It isn't great. Most users won't assume malice when an app crashes. And if they reopen it a few times your chance of succeeding goes up quickly. But this is also assuming that you need a single pointer tag to exploit something. If you need more you need to get even luckier.

So it definitely isn't perfect protection. But it isn't trivial to bypass.

Re: Memory Integrity Enforcement

#202

Post by kevincox »

aloha2436 wrote: post #133
bergfest wrote: post #52

With EU chat control, the state will be on my device, having access to everything they want, decide what I can and cannot do. Once Google forces WEI on us, the whole web will get locked down. And secure boot and now MIE will make sure we can never take back our freedom.

> MIE will make sure we can never take back our freedom. Is the implication here that making phones more secure is... bad? Because it makes jailbreaks harder to develop?

Yeah, this is weird logic to me. If you want control of your computing don't buy Apple hardware and hope to find an exploit. But hardware that supports running your own software without fighting you.

Re: Memory Integrity Enforcement

#203

Post by dns_snek »

kevincox wrote: post #202
aloha2436 wrote: post #133

Earlier quoted context omitted.

> MIE will make sure we can never take back our freedom. Is the implication here that making phones more secure is... bad? Because it makes jailbreaks harder to develop?

Yeah, this is weird logic to me. If you want control of your computing don't buy Apple hardware and hope to find an exploit. But hardware that supports running your own software without fighting you.

> Buy hardware that supports running your own software without fighting you.

It will be very hard to buy something that won't exist in the near future. This rhetoric should've died a decade ago.

Re: Memory Integrity Enforcement

#204

Post by kevincox »

dns_snek wrote: post #203
kevincox wrote: post #202

Earlier quoted context omitted.

Yeah, this is weird logic to me. If you want control of your computing don't buy Apple hardware and hope to find an exploit. But hardware that supports running your own software without fighting you.

> Buy hardware that supports running your own software without fighting you. It will be very hard to buy something that won't exist in the near future. This rhetoric should've died a decade ago.

Maybe, but it exists now. Maybe if more people demanded this hardware then it would be more popular and not at risk of extinction. I don't know what rhetoric you are taking about? Recommending buying stuff that supports your wishes seems like pretty reasonable advice.

Re: Memory Integrity Enforcement

#205

Post by snowwrestler »

superkuh wrote: post #30

This is the opposite of fun computing. This is commercial computing who's only use case it making sure that people can send/receive money through their computers securely. I love being able to peek/poke inside and look at my processes ram, or patch the memory of an executable. All this sounds pretty impossible on Apple's locked down systems. They're not so much general purpose computers anymore as they are locked dow…

It’s a shame you’re getting downvoted because I think you’re correct, and this is a perfectly valid opinion to hold.

I would respond by saying that sometimes I actually want a locked-down bank terminal (when I’m banking for example), and I appreciate the opportunity to buy one.

Computing hardware in general is way less expensive and more abundant than it used to be, so there are still many options in the marketplace for people to peek and poke into.

Re: Memory Integrity Enforcement

#206

Post by pizlonator »

jrtc27 wrote: post #153
pizlonator wrote: post #72

Earlier quoted context omitted.

I think the intra object issue might be niche enough to not matter. And CHERI fixes it only optionally, if you accept having to change a lot more code

Where studies suggest "a lot" is sub-0.1%. For example, https://www.capabilitieslimited.co.uk/_files/ugd/f4d681_e0f2... was a study into porting 6 million lines of C and C++ to run a KDE+X11 desktop stack on CHERI, and saw 0.026% LoC change, or ~1.5k LoC out of ~6 million LoC, all done in just 3 months by one person. That's even an overestimate, because it includes many changes to build systems just to be able to cro…

Does that study include enabling intra object overflow protection, or not?

When I say that this optional feature would force you to change a lot more code I’m comparing CHERI without intra object overflow protection to CHERI with intra object object overflow protection.

Finally, 6 million lines of code is not that impressive. Real OSes are measured in billions

Re: Memory Integrity Enforcement

#207

Post by pizlonator »

saagarjha wrote: post #186
vayup wrote: post #161

Earlier quoted context omitted.

In theory, it is a 1/15 chance of successful attack. Which is a terribly low success rate of attack prevention. In practice, it is 15/16 chance of detection of the exploit attempt. Which is an extraordinarily high rate of detection, which will lead to a fix by Apple. Net net, huge win. But I agree they come across as overstating the prevention aspect.

1/16 is a miserable rate for commercial spyware; it would be very difficult to sell this kind of product for a remote 0- or 1-click attack.

It’s miserable today because you’d be competing with others selling deterministic attacks.

But what if the only thing available to purchase is 1/16 or 1/256? Then maybe it’s not so miserable

Re: Memory Integrity Enforcement

#208

Post by amelius »

jahooligan wrote: post #167

"There has never been a successful, widespread malware attack against iPhone. ..." b your iphones BEEN pwned for YEARS and it was done in minutes LOL. gtfoh with help from ChatGPT: Apple claims “never been a successful iPhone malware attack” Reality: WireLurker, Masque, XcodeGhost, YiSpecter, jailbreak 0-days, Pegasus/Predator/Reign 0-clicks. iPhones pwned for yrs — by kids in pajamas

Yes, but with MIE there will come an end to that, hopefully.

The business model of Pegasus et al. will be gone.

Re: Memory Integrity Enforcement

#209

Post by dns_snek »

kevincox wrote: post #204
dns_snek wrote: post #203

Earlier quoted context omitted.

> Buy hardware that supports running your own software without fighting you. It will be very hard to buy something that won't exist in the near future. This rhetoric should've died a decade ago.

Maybe, but it exists now. Maybe if more people demanded this hardware then it would be more popular and not at risk of extinction. I don't know what rhetoric you are taking about? Recommending buying stuff that supports your wishes seems like pretty reasonable advice.

> I don't know what rhetoric you are taking about.

The rhetoric of blaming consumers for buying the wrong product when they complain about hostile features on Apple's side of the duopoly, and then blaming them again when they switch to Android and complain about hostile features on that side.

The rhetoric of blaming the consumers for simply "not demanding" what we want with enough conviction. It's an asinine thing to suggest because freedom to install and customize has been the headline feature of Android since day 1, but they're killing it anyway because the duopoly doesn't give a shit about what we want. They know that they can make more money and they know that we don't have a choice.

> Recommending buying stuff that supports your wishes seems like pretty reasonable advice.

No, not when the market is a well-known abusive duopoly. That's either ignorant of the reality or just gaslighting.

Re: Memory Integrity Enforcement

#210

Post by [deleted] »

MBCook wrote: post #122
kridsdale3 wrote: post #32

Earlier quoted context omitted.

Presumably future M5 model Macs and iPads.

I hope so too, but I could see it being in the M6 instead. The 202X M-series don’t always have the same core revisions as the A-series. Sometimes they’re based on the cores from 202X-1. Given how nice a feature it is I certainly hope it’s in the M5.

[deleted]
Post reply on HN