firer

Hah, not trying to pass off as human. Just communicating with my fellow men in black ;)

To be as explicit as possible: whether disclosing this publicly actually did more good then harm is not that clear cut. Even if accounting for all the second order effects.

Regardless, as a business you'd still be compelled to publish, because you've already poured resources into this research, there's still a chance to gain something, and there is enough plausible deniability about your true priorities.

All too common... It's sad yet understandable how a company would not prioritize security.

At the same time, it's also understandable how a security start-up, upon (rightly) getting fed up waiting, decide to publicly disclose, as a way to scrape some PR out of the sunk cost. Public disclosure has a place. But if you truly care about helping, you could do more than bumping on HackerOne and messaging the CISO once on LinkedIn.

Maybe I'm too cynical but it truly feels like nobody actually cares at this point.

From what I understand, the copy fail bug was found by researcher who noticed something weird and then using AI to scan the codebase for instances where that becomes a problem.

I bet that with a slightly looser prompt/harness, the LLM could have found these twin bugs too.

Yet at the same time, I also think that if the human researcher had manually scanned the code, he'd have noticed these bugs too.

FWIW I do think LLMs are great tools for finding vulnerabilities in general. Just that they were visibly not optimally applied in this case.

There are two vulnerabilities here.

The RxRPC one is definitely a different root cause (although caused by a very similar mistake).

For the ESP one it's a bit harder to tell. I don't think the wrong thing was fixed, just that there was a very similar bug in almost the same spot. Could be wrong about that though.

SUID mitigations have nothing to do with the vulnerability itself - just the exploit.

If there's a root cronjob that runs a world readable binary, you could modify it in the page cache and exploit it that way.

Modifying the page cache is a really strong primitive with countless ways to exploit it.

My immediate reaction was the same.

But this is very similar to Copy Fail, and I'm assuming there was an assumption that others might also discover this soon as well. Hence the urgency.

At least that's my charitable interpretation.

This is very similar in root cause and exploitation to Copy Fail.

Which illustrates pretty well something that's lost when relying heavily on LLMs to do work for you: exploration.

I find that doing vulnerability research using AI really hinders my creativity. When your workflow consists of asking questions and getting answers immediately, you don't get to see what's nearby. It's like a genie - you get exactly what you asked for and nothing more.

The researcher who discovered Copy Fail relied heavily on AI after noticing something fishy. If he had to manually wade through lots of code by himself, he would have many more chances to spot these twin bugs.

At the same time, I'm pretty sure that by using slightly less directed prompting, a frontier LLM would found these bugs for him too.

It's a very unusual case of negative synergy, where working together hurt performance.

System partitions being non-writable has nothing to do with the vulnerability - it allows modifying the cache of any file that you can open for reading.

Not using setuid anywhere means you'd have to build a slightly more clever exploit, but it's still trivial - just modify some binary you know will run as root "soon".

But... I didn't check, but IIRC the untrusted_app secontext that apps run in is not allowed to open AF_ALG sockets - so you can't directly trigger the vulnerability as a malicious app. Although it might be possible in some roundabout way (requesting some more privileged crypto service to do so).

Yeah, totally agree now that I've looked into it more.

If OSS models are equally up to the task, why not find novel vulnerabilities?

To be fair, in the same blog post Anthropic mentioned costs in the tens of thousands of dollars per project looked at it. So it's a big ask to do an experiment that compares. Would love to see it though.

Open source models found the same bugs? Sure, if you tell them "here is a for which may contain a vulnerability, look for a big in how function XYZ handles ABC"

In one of Anthropic's blog post, they describe that that's basically what they did too. They run the agent many times, each time specifying a different file to focus on. [1]

From my experience as a security researcher, manually finding a fishy file and sicking even sonnet 4.5 yields great results for most memory corruption bugs.

No comments otherwise. I don't have a clue as to who that guy is, and I haven't watched the video yet. You might be right overall.

[1] https://red.anthropic.com/2026/mythos-preview/

Edit: looked at the open source model claims - I agree that they suck. Basically all the details are given away in the prompt - not just the file.

Security efforts are not evenly distributed, even within a single project. This includes both the thinking that the developers put in, and the scrutiny given to a piece of code by researchers.

The initial batch of publicly disclosed vulnerabilities by Mythos demonstrates that perfectly. None of the bugs themselves are especially interesting or complex, in my opinion. They were found by applying effort to a very large amount of code which included under-scrutinized areas, where bugs hid. Yes, even in projects like Linux and OpenBSD there are many pieces of code that aren't that properly vetted, because of the finite amount of developer/researcher time allotted.

The fact that this effort is much cheaper does indeed change things. But really strong sandboxing solutions, such as gvisor or firecracker, do a really good job of having very little attack surface, all of which is heavily scrutinized.

Until we see more of the bugs that were found, it remains to be seen whether or not the post's premise about sandboxes is correct.

I agree with the general sentiment, but it seems fair to me that an old "lifetime" license won't have access to new features.

I love this stuff. If anybody wants another outlandish example here is an emulator I built: https://github.com/DanielFi/sqlite-vm/blob/main/emulator.sql

Fuzzing data flow separately from control flow is an interesting idea

I can believe that it dramatically speeds up finding certain bugs, but I doubt that it can reach a large class of complex vulnerabilities, which in the case of high value targets is probably all that's left.

The PHP interpreter isn't much of an interesting target, since it (usually) doesn't accept user input, even if it does power a significant part of the web.

For that reason, it's much less researched and still has low complexity bugs.

More robust interpreters such as JavaScript's V8 will probably fare much better against data flow only fuzzing. Bugs in V8 tend to combine both data flow and control flow[1].

[1] https://googleprojectzero.blogspot.com/2021/01/in-wild-serie...