[simjnd]

FFMPEG has consistently expressed their frustration with the fact that there is a large number of people willing and eager to publish vulnerabilities found in the project, but a comparatively minuscule number of people willing to work on patches to fix them.

[LegionMammal978]

On the other hand, there's been an endless parade of recent posts from other FOSS maintainers saying "we don't want your drive-by PRs": it's not hard to see people getting dissuaded from the whole dance of determining whether a project is receptive at all, then whether it has a reasonable number of hoops for outsiders to jump through.

Now, personally, when I file a bug report for a FOSS project I like to suggest an underlying cause and fix if I can figure it out, but I more rarely just submit a PR outright.

[ftchd]

If I have to choose between no PR and a "drive-by PR" where the author doesn't understand the changes to have a discussion, or isn't available to do changes and expects me to "take it from there", then I'd much rather go with "no PR" for the sake of everyone.

[sph]

On the third hand, pestering and shaming open-source maintainers because they don't accept your PR is how you get the XZ backdoor situation.

[xboxnolifes]

There is a different dynamic between this and that.

[j1elo]

Well this is nothing but an obvious expectation given the technical level required for doing good quality contributions, no?

I felt this is kinda like there being a large number of people willing to send spam email, but a comparatively minuscule number of people willing to work on ML filters to block it.

[simjnd]

You could assume that if someone has the technical level to identify a vulnerability and how to exploit it, they probably have the technical level to fix it.

In most cases researchers have no interest in actually "making the software better" and publishing vulns is just a way to increase their cred to land a better job.

FFMPEG's position as a well know very popular open source project means it's very interesting for this type of researcher to find a vuln and put their name on it.

It's an exhausting dynamic.

[codedokode]

If there are so many vulnerabilities, should not they change approach to development, for example, use memory-safe languages, static analysis, do not use dubious "hacks" that break it?

[ivanjermakov]

Memory safety and critical performance rarely go together. Big chunk of FFmpeg is written in assembly to sqweeze most hardware performance.

https://news.ycombinator.com/item?id=43140614

[IshKebab]

Sure but it seems like most of these vulnerabilities are being found in the C code.

[bybrooklyn]

Rust could help with this!

[leonidasrup]

It would be interesting to see the results from a fuzzer, developed for FFmpeg style assembly code.

[cryo32]

No. They tried that with coreutils and look what happened. More CVEs.

99% of what I throw though ffmpeg is trusted i.e. I created it. It’s not a major risk.

[acdha]

coreutils was a category error: they took a set of tools which were not very exposed to memory safety errors and rewrote them in a language which does nothing to prevent the kind of logic errors coreutils has suffered from (mostly races around file operations). It’s like complaining that an airbag didn’t save you after driving into a lake.

In contrast, ffmpeg is exactly the sweet spot for a memory-safe language with those complex decoders operating on data which is often untrusted. I wouldn’t suggest a project of that scale lightly but it’s at least a near-perfect fit on the problem domain.

[krageon]

The coreutils rewrite was shit because of the license change. Most of the other founding ideas were also bad as you say, but the license change was absolutely a much worse signal. Just a bunch of people rolling over and showing big corps their belly. And for what? So they can be more exploited by people that treat them like cattle.

[anoneng]

I would say it’s the opposite. coreutils is core utils, you cannot write shell scripts without them, they are widely and almost unavoidably used in trusted environments. They are also relatively simple.

With ffmpeg, anyone who knows anything about secure application development in the past 20 years knows that it is a huge security tarpit and throwing it untrusted inputs in trusted environment is asking to be owned. You thoroughly sandbox that shit. That’s true for all untrusted media conversion, but absolutely with ffmpeg.

[zahlman]

> you cannot write shell scripts without them, they are widely and almost unavoidably used in trusted environments.

True.

That doesn't make them "very exposed to memory safety errors".

[acdha]

My point about coreutils was that they’re rarely used in situations where an attacker can provide arbitrary input - it’s more like race conditions with code already running on the same system trying to escalate access – so what you need to protect against are things like race conditions around file operations or symlink safety.

[IshKebab]

Rust does not do "nothing" to prevent logic errors. On the contrary, its strong type system makes them much less likely than in C.

Also security isn't the only reason to prefer Rust to C.

But I do agree ffmpeg would see a much bigger benefit from being written in Rust.

[acdha]

Look, I like Rust and ported every bit of C I used to it a decade ago but this is not a compelling argument. The coreutils rewrite is an existence proof that the typing system doesn’t motivate this class of error and a moment’s thought would explain why (you’d have to be very familiar with the attack patterns to know to create types like “handle to private file failing if the name exists” and they weren’t).

What could help would be a modern API implementing the same patterns that GNU coreutils evolved over the last 4 decades but that’d be less the language than the library and it’d only go so far because some of those utilities legitimately need to things which are otherwise rare in most applications.

[codedokode]

In case with coreutils, as I remember, there were mostly race conditions. Not memory safety issues. Maybe we just need better I/O libraries.

[uecker]

Or use a buffer abstraction in C. This is not exactly rocket science. The "this is impossible to prevent in C" nonsense does far more harm than good.

[shermantanktop]

Errors are easily found and corrected for a modest one-person project in C.

But we’re combining probability of error creation (which is effectively constant) and the limits of human cognition.

Some things are impossible at one scale, become possible at another, and become inevitable at yet another.

[codedokode]

To be fair, C is a pain to use, so it is better to improve Rust. It is annoying when for example, you have to free several allocated structures when there is an error in the middle of a functon.

[uecker]

I personally like to use C and find Rust annoyingly complex. I think it may be an alternative to C++, but C++ is also too complex for my taste. I do not find it annoying to free several allocated structures when there is an error, but one could also automate this with a often used extension.

There is also the question whether trading memory safety against supply chain risks is really worth it.