The simplest approach to whitelisting libraries won't work, since the malicious color parser can just call the whitelisted library.

A different idea: Special stack frames such that while that frame is on the stack, certain syscalls are prohibited. These "sandbox frames" could be enabled by default for most library calls, or even used by developers to handle untrusted user input.

Thanks, it's great to see all the issues you raise.

On the other hand, it seems about as hard as I was imagining. I take for granted that it has to be a new language -- you obviously can't add it on top of Python, for example. And obviously it isn't compatible with things like global monkeypatching.

But if a language's built-in functions are built around the idea from the ground up, it seems entirely feasible. Particularly if you make the limits entirely around permissions around data communication -- with disk, sockets, APIs, hardware like webcams and microphones, and "god" permissions like shell or exec commands -- and not about trying to merely constrain resource usage around things like CPU, memory, etc.

If a package is blowing up your memory or CPU, you'll catch it quickly and usually the worst it can do is make your service unavailable. The risk to focus on should be exclusively data access+exfiltration and external data modification, as far as I can tell. A package shouldn't be able to wipe your user folder or post program data to a URL at all unless you give it permission. Which means no filesystem or network calls, no shell access, no linked programs in other languages, etc.

tbh none of that sounds particularly bad, nor do I think capabilities are necessary (but obviously useful).

we could literally just take Go and categorize on "imports risky package" and we'd have a better situation than we have now, and it would encourage library design that isolates those risky accesses so people don't worry about them being used. even that much should have been table stakes over a decade ago.

and like:

>No language has such an object or such interfaces in its standard library, and in fact “god objects” are viewed as violating good object oriented design.

sure they do. that's dependency injection, and you'd probably delegate it to a dependency injector (your god object) that resolves permissions. plus go already has an object for it that's passed almost everywhere: context.

perfect isn't necessary. what we have now very nearly everywhere is the most extreme example of "yolo", almost anything would be an improvement.

Thanks, this was a good overview of some of the challenges involved with designing a capability language.

I think I need to read up more on how to deal with (avoiding) changes to your public APIs when doing dependency injection, because that seems like basically what you're doing in a capability-based module system. I feel like there has to be some way to make such a system more ergonomic and make the common case of e.g. "I just want to give this thing the ability to make any HTTP request" easy, while still allowing for flexibility if you want to lock that down more.

"it exists as a niche feature that few use and fewer understand" isn't exactly "mainstream" IMO (it's significantly less common from what I've seen than manual classloader shenanigans, for example). But yes, it's nice that it exists, and I wish it were used more - it'd catch low-effort stuff like this one was.

yea, just look at the state of many C projects. it's rather clearly worse in practice in aggregate.

should it be higher friction than npm? probably yes. a permissions system would inherently add a bit (leftpad includes 27 libraries which require permissions "internet" and "sudo", add? [y/N]) which would help a bit I think.

but I'm personally more optimistic about structured code and review signing, e.g. like cargo-crev: https://web.crev.dev/rust-reviews/ . there could be a market around "X group reviewed it and said it's fine", instead of the absolute chaos we have now outside of conservative linux distro packagers. there's practically no sharing of "lgtm" / "omfg no" knowledge at the moment, everyone has to do it themselves all the time and not miss anything or suffer the pain, and/or hope they can get the package manager hosts' attention fast enough.

Well, consider that a lot of these functions that were exploited are simple things. We use a library to spare ourselves the drugdery of rewriting them, but now that we have AI, what's it to me if I end up with my own string-colouring functions for output in some file under my own control, vs. bringing in an external dependency that puts me on a permanent upgrade treadmill and opens the risk to supply chain attacks?

Leftpad as a library? Let it all burn down; but then, it's Javascript, it's always been on fire.

For better or worse it is often less work to create a dependency than to maintain it over its lifetime. Improvements in maintenance also ease creation of new dependencies.

I wouldn’t go for painful that much. The main issue is transitive dependencies. The tree can be several layer deep.

In the C world, anything that is not direct is often a very stable library and can be brought in as a peer deps. Breaking changes happen less and you can resolve the tree manually.

In NPM, there are so many little packages that even renowned packages choose to rely one for no obvious reason. It’s a severe lack of discipline.