Comment by Despegar
2 years ago
I'm curious to know from experts if there's anything Apple can do to create a step-change in terms of security of iPhones? Like if the going rate for a zero day is $1 million, is there anything Apple can do that can drive that up to $2 or $3 million? Or is it just going to be a perpetual cat and mouse game with no real "progress"?
I am by no means a security expert whatsoever. Period. But reading the article carefully, there is a step in the chain of exploits (CVE-2023-32435) which depends on exploiting Safari. Apple implemented a "Lockdown mode" (https://support.apple.com/en-us/105120) which might have handled this (?).
Answering more broadly to your question, the "step-change" that you're asking for is precisely the "Lockdown mode" in iOS devices. It disables most of the features in order to reduce the attack surface of the device.
If you read a better article with technical details [1], you'll see that Apple SOCs contain a "feature" (that resembles a debugging tool) that allows to bypass memory protection by writing into undocumented and unused GPU registers. Apple locks down kernel memory to stop exploits, but these registers allow to bypass the lock.
This vulnerability is they key vulnerability without which all the exploit chain would be useless.
[1] https://securelist.com/operation-triangulation-the-last-hard...
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The Safari vulnerability wasn't necessary (the device was completely owned before that), and was really just a "nice to have" - it allowed verification of the targeted user and, presumably, customizable malware delivery. From the article, if you look at the bullet points under the Kaspersky diagram of the exploit chain:
> After exploiting all the vulnerabilities, the JavaScript exploit can do whatever it wants to the device and run spyware, but attackers chose to: a) launch the imagent process and inject a payload that cleans the exploitation artifacts from the device; b) run the Safari process in invisible mode and forward it to the web page with the next stage.
In other words, if looking at the diagram, https://cdn.arstechnica.net/wp-content/uploads/2023/12/trian... , it's completely "game over" once you get to the skull icon in the lower left corner, and the Safari exploit is after that.
Yeah, lockdown mode might have handled it. If I'm reading the article right, the first step of the exploit was a PDF file sent with iMessage.
When I tried out lockdown mode out of curiousity, I found that it was aggressive about blocking PDF viewing. I quickly bailed on it because I often read research papers on the web, and it switched them from view to download.
It could author its format parsers in https://github.com/google/wuffs, and make them BSD-like open source to maximize adoption.
An even bigger change: It could allow users to choose their iMessage client freely. Why not open up the protocol? I’m sure a security focused client would be popular and in the grand scheme of things easy to author.
Perhaps they could open up more of the OS and apps. Perhaps their claims about the security of users and the App Store is kind of BS.
I struggle to believe that a third party iMessage iOS app would be a security improvement, beyond Lockdown Mode https://support.apple.com/en-us/105120.
Either a third party app would still use the same vulnerable frameworks as iMessage, or they would re-implement them potentially with more vulnerabilities, or just not implement the features, which is what Lockdown Mode gives you.
One could argue the same about alternatives to Safari, and yet Chrome has proven to be more secure than Safari (based on Pwn2Own results).
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You do realize that this is an extremely complicated exploit which is not being used on the average user, right?
And being open source hasn’t prevented Android from being much more vulnerable to these kinds of exploits.
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Sure. Rewrite sensitive parts of their stack in memory safe languages. They have Swift after all. A lot of the iOS security improvements over time have really been more like mitigations that try to contain the damage when the giant of pile of decades old C gets exploited.
That is exactly their plan. Swift could always link into C applications, and they have recently come out with C++ interoperability [1] so things like WebKit etc. can start having parts re-written or new parts written from the start in Swift so they can gradually replace C and C++ codebases instead of trying to rewrite everything (which sucks because even for things much, much less complex than WebKit, you can have a team working for three years working on a replacement and it’ll have less features than the original had when you started).
They’re even working on an embedded subset for embedded devices so things like microcontrollers like battery management, the Secure Enclave etc. can run it.
1. https://m.youtube.com/watch?v=lgivCGdmFrw
They’re working on it, but a memory-safe language doesn’t help you in some of the surface that the attackers exploited here.
I think memory safety + integer overflow checking by default would have blocked many of these. Not the hardware mitigation disable but getting to the point where that matters required some safety problems that can be excluded by better languages.
It's already 2-3 million +. Apple has amazing security, especially for the Iphone and continously monitors it and dishes out silent patches. For a REALLY high level example, it restricts system calls per process and requires all calls to be signed with an apple key, AND it restricts who you can do the system call to, these are continuously monitored and updated. Not only this, but persistence on Iphone is effectively dead, meaning you have to reinfect the device after every reboot. One of the big things you notice in the article is the use of ROP, apple requires every executable page to be signed by them, hence why you have to have these assfisting of rop chains.
2-3 million dollars is not “amazing”. That is less than the cost to open a McDonalds. You can get a small business loan in the US for more than that. There are literally tens of millions of people in the world who can afford that. That is 1/5 the cost of a tank.
2-3 million dollars is pocket lint to people conducting serious business, let alone governments. It is at best okay if you are conducting minor personal business. This ignores the fact that attacks at the 2-3 million dollar range are trivially wormable. If you had actual cause to hack every phone you are only incurring marginal cents per attack. Even relatively minor attacks like targeting 10,000 people are less than one phone of cost per attack.
> 2-3 million dollars is not “amazing”.
I don't know. $2-3m for reading code in Ghidra and throwing stuff at a wall until something sticks? Maybe some fuzzing, etc.
I get that you theoretically could find an exploit that for example, you send to 100 known wealthy people, and with it you steal saved cookies + device IDs from financial apps and then try to transfer their funds/assets to an account you control but...
Could you really pull that off 100 times before Apple catches on?
I guess you could... easily... now that I think about it.
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That is good info, but why does Apple make it non obvious on how to reboot an iOS device and AFAICT there is no way to schedule a regular reboot.
Need to restart your non responsive iPhone, hope you have some dexterity...
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Force restart iPhone
If iPhone isn’t responding, and you can’t turn it off then on, try forcing it to restart.
We'd need to scrape decades of work in hardware and software for that.
Modern software sits on a foundation that was thought for a different era. They didn't have in mind the current challenges in terms of security and scale.
What do you mean "no real progress"? The price used to be $100.
I mean progress from today.
I don't understand what you mean. They've always been making progress, driving the price up. They can just keep doing what they're doing, and there will be progress from today.
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I mean, this is already an extremely complex chaining of exploits that requires extremely sophisticated research. I can assure you that this is not being used on the average person.