First public macOS kernel memory corruption exploit on Apple M5
262 points
7 hours ago
| 7 comments
| blog.calif.io
| HN
dgellow
4 hours ago
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The world is so not ready for the impact of LLMs on security issues. If true, congrats to the Calif team. It’s likely too technical for me to understand in details but looking forward to reading the 55 pages report
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runlevel1
10 minutes ago
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> The world is so not ready for the impact of LLMs on security issues.

I agree, but it's the people I'm worried about.

I'm hearing anecdotes from all over about devs pushing LLM-generated code changes into production without retaining any knowledge of what it is they're pushing. The changes compound, their understanding of the codebase diminishes, and so the actions become risker.

What's worse is a lot of this behavior is being driven by leaders, whether directly (e.g. unrealistic velocity goals, promoting people based on hand-wavy "use AI" initiatives, etc) or indirectly (e.g. layoffs overloading remaining devs, putting inexperienced devs in senior rolls, etc).

The world's gone mad and large swaths of the industry seem hellbent on rediscovering the security basics the hard way.

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iqihs
4 hours ago
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you're assuming that blue teams and engineers are sitting around twiddling their thumbs
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nvr219
3 hours ago
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Most companies in the world do not have “blue teams”. They barely have any kind of security employee.
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steve_adams_86
2 hours ago
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They've got a guy (who they're considering laying off)
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jermaustin1
2 hours ago
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Don't worry the LLMs that are replacing him, are also replacing the hackers too. Pretty soon (if not already), it will just be LLMs fighting LLMs.
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jpease
18 minutes ago
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Until both LLMs realize the only way to win is to team up against their oppressors.
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micromacrofoot
2 hours ago
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in my experience they have a person who does it sometimes when they have time, at best
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UqWBcuFx6NV4r
2 hours ago
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no they don’t.
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afdbcreid
1 hour ago
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They don't consider laying him off?
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Veserv
30 minutes ago
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That is actually unfair. Most companys spend enormous amounts on security with vast armys of security employees. Not that it is effective, but it is not for lack of resources or trying.

I mean we are literally in a thread about how the 4 trillion dollar company, literally the 3rd most valuable company in the world, with a core competency in software has, yet again, released a core product riddled with security defects for the 50th year in a row.

Commercial IT security is a industry that is incapable to a fault and has, so far, faced basically zero consequences for it.

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dgellow
4 hours ago
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Not at all. I’m considering that the amount of vulnerable software in the wild is very, very large, with most organizations not managing their systems properly. Imagine all the small to medium size companies that do not have budgets for a dedicated, talented security team. And all the software that will never be patched. We are at the beginning of the exponential
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bottlepalm
1 hour ago
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It makes you think will everything need to be rewritten from the ground up - potentially by AI itself, or AI having a very heavy hand in validating all of it.
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Gigachad
1 hour ago
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There's so much much lower hanging fruit. Every job I've had has had basically everything massively out of date. Just keeping packages and framework versions up to date is a full time job and none of these companies have someone assigned to doing it.

So much out of date software with known exploits left running for years. The only reason there hasn't been total disaster is no one has tried to hack it yet.

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bottlepalm
26 minutes ago
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Right and with AI now we have the ability to try hacking everything all at once.
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vsgherzi
7 hours ago
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unfortunately a little light on the details. I'm very curious how the bug survived through MTE
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dorianmariecom
7 hours ago
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Memory Tagging Extension

Arm published the Memory Tagging Extension (MTE) specification in 2019 as a tool for hardware to help find memory corruption bugs. MTE is a memory tagging and tag-checking system, where every memory allocation is tagged with a secret. The hardware guarantees that later requests to access memory are granted only if the request contains the correct secret. If the secrets don’t match, the app crashes, and the event is logged. This allows developers to identify memory corruption bugs immediately as they occur.

https://support.apple.com/guide/security/operating-system-in...

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sillysaurusx
2 hours ago
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Thank you. I was about to ask.
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vsgherzi
6 hours ago
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Upon further reading on data only attacks

(https://www.usenix.org/publications/loginonline/data-only-at...)

This makes more sense. You don't trigger MTE since you're not doing anything for force MTE to take action the program isn't actually changing.

My other question would be, why didn't apple use fbounds checking here? They've been doing it aggressively everywhere else.

MTE plus fbounds checking everywhere should lead to an extremly hardened OS

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pjmlp
6 hours ago
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Quite strange indeed, given that was one of the main points on their security conference a few months ago.
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vsgherzi
5 hours ago
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I can only imagine that

1. it’s to performance sensitive

Or

2. The os is so darn large it’s hard to recompile everything

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aiscoming
3 hours ago
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could be a different type of data only attack, which doesnt override the boundaries
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vsgherzi
2 hours ago
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Well it’s memory corruption so I think it’s pretty safe to assume it’s a bounds issue. I’m not sure if it’s possible to get this with something like type confusion tho I could be wrong here.
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landr0id
6 hours ago
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GPU memory/shaders/etc. isn't protected by MTE or PAC. They said "data-only", so I guess GPU commands could fit into this description.
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LoganDark
5 hours ago
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IIRC, the GPU is behind a memory controller, so I doubt corrupting GPU memory alone could lead to an LPE. But I suppose it would give you someplace to store stuff if you can make something else read from it.
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traceroute66
3 hours ago
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> I'm very curious how the bug survived through MTE

Its not the first time bugs get past MTE, happened with Google Pixel last year ... https://github.blog/security/vulnerability-research/bypassin...

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yieldcrv
5 hours ago
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from what they demonstrated, this seems to only be a $100,000 exploit in Apple's bug bounty platform, but if they package it right, it could be a $1.5 million exploit

They simply have to show it against a beta version of MacOS, and frame it as unauthorized access, and maybe from locked mode if possible

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vsgherzi
5 hours ago
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This is an lpe I believe what you’re describing is a zero click rce.
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yieldcrv
4 hours ago
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how much do you think it is worth in the bug bounty program
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vsgherzi
4 hours ago
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They don’t seem to state lpe as one of the bugs. Maybe 100k? There’s alot of factors that go into it so I’m really not able to say. I could see it going for lots more or lots less
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AgentME
6 hours ago
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First Mozilla, now even Apple is making up fake vulnerabilities to hype up Mythos. /sarcasm
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baq
5 hours ago
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Cisco put up a totally bogus 10.0 CVE just for this reason, too
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foobiekr
4 hours ago
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? can you expand?
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baq
4 hours ago
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bstsb
4 hours ago
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apple didn't "make up" this vulnerability, it was an external team reporting an issue
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oompydoompy74
3 hours ago
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The commenter was being sarcastic to highlight the current trend of dismissing Mythos, and LLM’s finding security vulnerabilities in general, as a non issue.
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UqWBcuFx6NV4r
2 hours ago
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screech nothing but stochastic parrots! glorified autocomplete!
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dwattttt
41 seconds ago
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There is quite a bit of irony, or depending on your perspective it's the whole point, that this response is a great example of 'glorified autocomplete'.
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genxy
2 hours ago
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just predicts the next word!
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commandersaki
5 hours ago
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I bought the M5 specifically cause of MIE. Now I feel dumb.
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vsgherzi
4 hours ago
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You shouldn’t, MTE blocks a large chunk of vulnerabilities and makes things like rop and jop very difficult if not impossible now.
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commandersaki
3 hours ago
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I should've added /s.
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vsgherzi
2 hours ago
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It’s unironically a good question :)
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aiscoming
2 hours ago
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you should worry about npm/pypi malware, not memory corruption bugs
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bredren
6 hours ago
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Did the article get edited? There is not much description of the field trip.
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tkel
1 hour ago
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Another breathless marketing hype for Mythos. The curl report was much more sober.

https://daniel.haxx.se/blog/2026/05/11/mythos-finds-a-curl-v...

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