AI has another security problem

We all know about how MCP has fundamental flaws in how it handles authorization, how OpenClaw and its relatives open up local machines to exploits and the whole world of LLMs is a security nightmare𐠒. And we also are now hearing that Mythos, Anthropic’s latest model, can exploit all of the security flaws in all of the software ever and it’s so impressive that it was released ahead of time to everyone important so they could run it themselves and protect themsevelves from the oncoming onslaught of hackers equipped with it.

But AI has another, more fundamental security problem. Let’s say Mythos is real, and it costs something on the order of tens of thousands of dollars to find new exploits in the code of big open source projects that power millions of servers.

How expensive do you think it is to find exploits in closed source systems? It must be substantially less expensive: The depth of security in any system is a product of the number of eyes and hands that system has passed over. Each user of an open source system is one more possible misconfiguration that leads to a revelation of a problem to solve in an open library, and each year the code spends open is another year of eyes skimming or scanning the project identifying improvements and flaws.

Closed source software doesn’t have any of these benefits. No one who is using it is going to be able to freely draw a line from a failure they notice to a problem in the code, and layers of support teams between the users and the engineers who could look at the code will further hamper open discovery of problems.

No one is reading it passively other than those who are paid to, and they are famously not paid to keep it secure in general. Why spend time looking for ghosts of security problems when there’s a customer who needs a new feature at the end of the week?

But closed source companies pay for security audits, you say? They pay companies out the wazoo to analyze their codebases for problems passively! This is all true, and it’s all security theater. As a security-conscious engineer myself, I’ve interally documented dozens of security flaws, hoping to be allocated to fix them, and seen half a dozen security teams of auditors and all the static analysis tools in the business miss the interesting problems time and time again, instead finding “problems” like “you shouldn’t cast from an int64 to an int32” or “user input from CLI flags can be provided to this API endpoint”.

What does this mean for software? It means that large open source projects are still the best place to put your trust, and it also reveals a chink in the armor of Schrödinger’s AI bubble: if it is true that LLMs can find security problems in exchange for nominal funds, and if it persists that LLMs will produce large pieces of software by themselves with minimal or no human review, then the only programs that will be safe will be those which are not written by LLMs and which go through extensive human review. And the best match for those conditions, is open source.

LLM-written code is inherently less secure by it’s nature: models are trained on the average code i.e. insecure code, and it is produced with inherently less oversight than human-written code– pattern matching to achieve a desired result; If Mythos can do what Anthropic says it can, then every LLM-written codebase is a sitting duck.


(𐠒) see the top page of hackernews on any given day for references

Q: What if I use Mythos on my own code to make sure it isn’t vulnerable?

A: Anthropic’s existing code review tools are already prohibitively expensive. Should Mythos be opened up, it’ll be an order of magnitude more expensive than Opus 4.7. There’s substantial incentive for hackers to attack you, because they could gain millions in ransom, but it’s going to be a hard sell to your management to keep running tens of thousands in background scans as you release new updates, “just in case we find a big bug which could expose us to potentially higher costs”; companies building software in the age of Agile and LLMs do not want to spend this money on nothing (compared to what they could spend it on, on new features) and so they will not.

Q: What if I use Mythos to write the code? Won’t the security problems go away?

A: Assuming this is more affordable, not necessarily. Mythos’ current tests are presumably using prompts / a scaffolding specially targetting the identification of security flaws, and they were apparently run after the fact line-by-line. The configuration one uses to produce code won’t necessarily have the same traits, because LLMs do not think, they match patterns based on their inputs: if it lacks the same input structure which is being used in Anthropic’s current marketing push then we lose any confidence in its security analysis capabilities.

Q: What if Mythos is just hype?

A: Then this might be a smaller problem, but it’s still a problem; LLM-code defensibility isn’t any different, but the attacker might need more man-hours to produce the exploits.

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