[HN Gopher] Tachy0n: The Last 0day Jailbreak
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       Tachy0n: The Last 0day Jailbreak
        
       Author : todsacerdoti
       Score  : 249 points
       Date   : 2025-05-24 19:50 UTC (1 days ago)
        
 (HTM) web link (blog.siguza.net)
 (TXT) w3m dump (blog.siguza.net)
        
       | ivanjermakov wrote:
       | If this is the case Apple employed an amazing strategy. By
       | locking all ways to possibly root their devices they patch
       | vulnerabilities discovered for free by jailbreak devs.
        
         | ejpir wrote:
         | but they haven't, the article says the "private" community
         | still has exploits and apple patches them. The public, like the
         | dev, for some reason, don't anymore.
        
           | tptacek wrote:
           | They're exclusive to private communities because they're very
           | expensive, and getting more expensive over time; in other
           | words, Apple's strategy has driven the cost of exploiting iOS
           | up.
           | 
           | Anything public is dead, which is what you want to see.
        
             | bri3d wrote:
             | I'm not sure I agree with the premise here, although I
             | agree with the conclusion w.r.t Apple specifically.
             | 
             | I'm 100% positive from experience doing VR in several non-
             | iOS spaces that increased exploit value leads to fewer
             | published public exploits, but! This is not a sign that
             | there are fewer available exploits or that the platform is
             | more difficult to exploit, just a sign that multiple (and
             | sometimes large numbers) of competing factions are hoarding
             | exploits privately that might otherwise be released and
             | subsequently fixed.
             | 
             | As a complementary axiom, I believe that exploit value
             | follows target value more closely than it does exploit
             | difficulty, because the supply of competent vulnerability
             | researchers is more constrained than the number of
             | available targets. That is to say, someone will buy a
             | simple exploit that pops a high value target (hello, shitty
             | Android phones) for much more money than a complex exploit
             | that pops a low value target. There are plenty of devices
             | with high exploit value and low exploit publication rate
             | that also have garbage security.
             | 
             | With that said, Apple specifically are a special (and
             | perhaps the only) case where they are "winning" and people
             | are genuinely giving up on research because the results
             | aren't worth the value. I just don't think this follows
             | across the industry.
        
               | tptacek wrote:
               | I don't think I reach the deeper questions here, and
               | pretty much just get back to "if it was cheap, Apple
               | would have killed it already"; in that set of
               | circumstances there _can 't_ be viable public exploits
               | (or broad workable bug classes to fish from) to work
               | with.
               | 
               | Sucks if you're part of a public jailbreaking community,
               | but, of course, good if you're a user.
        
               | pona-a wrote:
               | But it's still more of obfuscation. You're effectively
               | reducing the pool of researchers to those most likely to
               | turn to the dark market. There's an entire zero-day
               | industry privately developing exploits, and the public
               | sees none of it. Sure, low-resource attackers can
               | probably forget about exploiting iOS, but stuff like
               | Pegasus still happens regularly.
        
               | tptacek wrote:
               | Literally the alternative is more viable vulnerabilities.
               | It's hard to understand a coherent argument that favors
               | that over what we have now. We're in this situation
               | because Apple has gotten good at killing whole bug
               | classes. That's exactly what users want.
        
               | bri3d wrote:
               | I agree with this. I also agree that there's no
               | preferable situation. Apple have done a great job
               | building mitigations and it shows in how difficult,
               | expensive, and rare it is to fully exploit their
               | platforms. I certainly wasn't intending to form a
               | counter-argument that public exploits existing would be a
               | positive signal, or that there's a preferable alternative
               | situation.
               | 
               | My only point was that "anything public is dead is what
               | you want to see" is not a particularly useful rubric in
               | general. I get nervous when I see statements that suggest
               | an absence of public exploit material or high "bid" price
               | for grey market exploits as evidence that a platform is
               | less vulnerable. My experience suggests this isn't really
               | how the market works in general. There are way too many
               | additional factors that affect both pricing and
               | publication to use "public exploit availability" or
               | "grey-market bid price" as a signal about a platform's
               | security posture overall.
               | 
               | Anyway, reading back, I realize that you specifically
               | weren't trying to draw that conclusion, but sibling
               | comments are now - and it seems to be a really easy trap
               | to fall into. See: every "security journalism" outlet
               | every time a broker posts an Android bid that's higher
               | than their standing iOS bid, or vendors and OEMs claiming
               | their devices are secure because no public exploits
               | exist.
        
               | maldev wrote:
               | IOS requires so many exploits in the chain since they
               | effectively sign system calls, and capabilities by each
               | app at two steps. So you may be able to interact with
               | another process, but only whitelisted processes. The
               | kernel is also Immutable so persistence is impossible.
               | They do a level of boundary checks that only Apple can
               | do, and also have special telemetry flags on critical
               | processes that either mean they're looking to end of life
               | a pathway.
               | 
               | No other OS can restrict on this level and it makes it so
               | not only do you need an exploit for say the Javascript
               | engine, you also need an exploit for like 10 other
               | pathways. The reason for this is since the kernel is
               | immutable and checked out the wazoo, you get "Jailbreaks"
               | by modifying different services and system processes and
               | getting a capability from those apps. Which is where the
               | exploit is required for them or an approved peer. But
               | apple also has telemtry for what each app is doing with
               | eachother.
        
           | hsbauauvhabzb wrote:
           | Is this actually true? Jailbreaks are more or less the same
           | exploits used by things like Pegasus, the exploits are
           | probably worth more to the individuals that discover them
           | than the ability to give their friends access to side loaded
           | apps
        
             | burnt-resistor wrote:
             | That's the rub of relative integrity. It's variably easier
             | for some to rationalize taking the cash, even if that giant
             | pile of coin is likely to lead to the imprisonment, deaths,
             | and/or torturing of others for better or for worse.
        
               | hsbauauvhabzb wrote:
               | My question wasn't about ethics and I'd rather keep it
               | that way.
        
           | numpad0 wrote:
           | Jailbreaks need an itch to scratch. There isn't one for
           | Ubuntu Desktop.
        
       | weinzierl wrote:
       | I've heard Apple pays a million for Jailbreaks now. That's the
       | lower bound for the price on the free market.
        
         | ThinkBeat wrote:
         | Is there a way to contact Apple to apply for millions of
         | dollars if one has a jailbreak?
         | 
         | X: Hi AppLE I haz jailb8?
         | 
         | Or is it via one of the intermediaries?
         | 
         | Or is there an email or some such that is published? (That will
         | not to straight to 1st level support and forgotten about)
        
           | charcircuit wrote:
           | https://security.apple.com/bounty/
        
         | conradev wrote:
         | > now
         | 
         | That boundary was broken in 2015, about a decade ago:
         | https://www.dailymail.co.uk/sciencetech/article-3301691/New-...
        
           | halJordan wrote:
           | That's cool, Apple's bug bounty didn't exist ten years ago.
           | Apple's bug bounty does max out at $1 million (although you
           | can get bonus multipliers up to $2mil). Just read the content
           | before throwing down the gotcha.
        
           | Thorrez wrote:
           | That 1M was not paid by Apple. It was paid by Zerodium, a
           | company that sold/sells vulnerabilities to attackers (e.g.
           | NSA).
        
         | lern_too_spel wrote:
         | That's the market rate. https://cyberscoop.com/zerodium-
         | android-zero-days-bounty/
        
           | andrepd wrote:
           | Well TIL that there are zero-day market makers...
        
             | tptacek wrote:
             | Bear in mind: different buyers and different price
             | structured. You can get more selling a vulnerability to CNE
             | shops (say: every intelligence organization in Germany),
             | but you'll be accepting more risk --- the payments are
             | effectively tranched (or, equivalently, back-loaded on
             | "maintenance" fees), and if the vulnerability dies you're
             | S.O.L. Apple also won't make you build all the reliable
             | exploitation enablement tooling a CNE buyer will. So: they
             | pay less.
        
       | yjftsjthsd-h wrote:
       | > The way he managed to beat a trillion dollar corporation was
       | through the kind of simple but tedious and boring work that Apple
       | sucks at: regression testing.
       | 
       | > Because, you see: this has happened before. On iOS 12,
       | SockPuppet was one of the big exploits used by jailbreaks. It was
       | found and reported to Apple by Ned Williamson from Project Zero,
       | patched by Apple in iOS 12.3, and subsequently unrestricted on
       | the Project Zero bug tracker. But against all odds, it then
       | resurfaced on iOS 12.4, as if it had never been patched. I can
       | only speculate that this was because Apple likely forked XNU to a
       | separate branch for that version and had failed to apply the
       | patch there, but this made it evident that they had no regression
       | tests for this kind of stuff. A gap that was both easy and
       | potentially very rewarding to fill. And indeed, after
       | implementing regression tests for just a few known 1days, Pwn got
       | a hit.
       | 
       | And now I wonder how many other projects are doing this. Is
       | anyone running a CI farm running historical vulnerabilities on
       | new versions of Linux/FreeBSD/OpenWRT/OpenSSH/...? It would
       | require that someone wrote up each vulnerability in automated
       | form (a low bar, I think), have the CI resources to throw at it
       | (higher bar, though you could save by running a random selection
       | on each new version), care (hopefully easy), and think of it
       | (surprisingly hard).
        
         | KennyBlanken wrote:
         | > And now I wonder how many other projects are doing this.
         | 
         | If by 'projects' you mean intelligence agencies, then I would
         | say it's safe to assume at least the G10 intelligence agencies
         | are doing this along with Russia, China, NK - and likely a huge
         | number of private groups.
        
         | bcoates wrote:
         | I think the underlying problem is that lots of orgs have siloed
         | out security stuff into its own workflow and its own class of
         | bugs.
         | 
         | It's basically Conway's law applied to the security/feature
         | development split.
         | 
         | So even if they have a build/release procedure with a mature
         | regression test suite it probably wouldn't have "security"
         | issues like this in it just as a matter of internal
         | organization
        
         | jdwithit wrote:
         | Yes, regression testing--making sure bugs you've fixed don't
         | return--is a standard part of QA. I did volunteer QA for
         | Mozilla in college a good 20 years ago (god that number is
         | horrifying) and they had an ever-growing suite of regression
         | tests. Mostly for rendering/layout or JavaScript engine bugs,
         | since part of reproducing and proving you'd fixed those was
         | creating a minimal test case. Which you could then easily throw
         | into the build pipeline.
         | 
         | Bugs are a fact of life, but burning time and money to fix them
         | only to have them return is the worst case scenario.
         | Organizations that care about quality are definitely investing
         | in regression testing. Unfortunately a whole lot of orgs give
         | QA zero respect and offshore it to the lowest bidder, if they
         | do it at all. It's absolutely insane to me that Apple wouldn't
         | have regression tests for jail breaks, some of the most high
         | profile bugs in history.
         | 
         | You can fairly criticize Mozilla for a number of things these
         | days. But they had a very robust QA and CI/CD setup in the
         | early 2000s with tools like Tinderbox and Bugzilla. When DevOps
         | came around and popularized it I was like wait, people weren't
         | already doing this stuff??? Turned out I had been living in a
         | bubble and that was not the norm at all.
        
           | gcau wrote:
           | I think they are referring to secretly regression testing
           | other peoples code (to check if patched exploits become
           | exploitable again).
        
           | bradknowles wrote:
           | Many years ago, I did a six month contract for Apple Retail
           | Software Engineering, to deliver a Jenkins CI/CD system for
           | the code that was used to communicate with the employees in
           | the stores, to allow those employees to communicate with each
           | other, to deliver training to them, etc....
           | 
           | There were multiple major components. There was the back-end
           | server system that ran on Linux. There was the content
           | creation system that ran on MacOS. There was the end-user
           | clients that ran on iOS and iPadOS. And there was an
           | extensive array of QA processes that they ran.
           | 
           | I ended up making minor changes to the code base for each of
           | those components, so that they could build on the Jenkins
           | server that was running underneath my desk (on an old Mac Pro
           | server that had been lying around).
           | 
           | And I can tell you that they had extensive regression tests
           | -- as of the time I was there, over five thousand of them.
           | Those took a really long time to run, which is why they
           | needed the Jenkins server instead of doing this stuff on
           | their laptops.
           | 
           | Now, I can't speak for developers anywhere else at Apple, but
           | I believe that they are well acquainted with the concept of
           | regression testing.
        
         | edoceo wrote:
         | There is a FOSS project I've seen but cannot remember the name
         | of currently (beer) but I do recall their test case directory,
         | one for each issue of merit. Thousand of them, easy. Might of
         | been Sqlite. Something to look up to. I guess if you're not
         | back porting fixes you'd likely not back port the tests either.
        
           | TheMatten wrote:
           | Glasgow Haskell Compiler project does this: https://gitlab.ha
           | skell.org/ghc/ghc/-/tree/master/testsuite/t...
           | 
           | Every test starting with T and a number is an example created
           | from a corresponding issue in their tracker. And there is,
           | well, a lot of them.
        
       | 0x38B wrote:
       | > forget everything you know about kheap separation, forget all
       | the task port mitigations, forget SSV and SPTM
       | 
       | This is like when you're speaking in a foreign language with a
       | friend and getting along fine, but in the next sentence they
       | begin describing brain surgery or nuclear physics, and your
       | understanding falls off a cliff.
       | 
       | Or that time I tried to interpret a conversation about blast
       | furnace renovations.
       | 
       | As far as jailbreaks go, I'm sad it's not a thing anymore; I
       | don't think I ever did anything useful with my jailbroken iPad,
       | but it was fun. Today I'd install a tethering app and UTM + a JIT
       | solution (1).
       | 
       | 1: SideStore looked promising, but my account was once a paid
       | Apple Developer account and I have 10 app IDs that won't expire,
       | so I can't install any apps like the aforementioned UTM, unless I
       | make a new account or pay again.
        
         | xandrius wrote:
         | I had my old iPhone 4 jailbroken and it was literally the only
         | way I would use an iPhone as my main device. Having lost that,
         | I switched back to Android which had caught up in many basic
         | features by then.
        
       | Tachyooon wrote:
       | I'm no security researcher, but this hits close to home for me
       | personally.
        
         | dmvdoug wrote:
         | Thoughts and prayers during your time of mitigation.
        
       | greggh wrote:
       | My favorite line from the whole post "I'd also like to thank
       | whoever unpatched the bug in iOS 13.0. That was a very cool move
       | too."
        
       | Hilift wrote:
       | > I can't possibly imagine where we'll be in 5 years from now.
       | 
       | I can. iMessage still allows device, account, and data takeovers.
        
       | peterburkimsher wrote:
       | Tethered or untethered? The article didn't say.
        
         | Retr0id wrote:
         | tachy0n is an LPE, so that's not really a relevant
         | classification. The jailbreak it was deployed as part of,
         | unc0ver, is "semi-untethered" afaik.
        
           | peterburkimsher wrote:
           | Cool, thanks for answering! unc0ver is this one, btw:
           | https://unc0ver.dev/
        
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       (page generated 2025-05-25 23:01 UTC)