Ffmpeg has an exceptionally terrible track record when it comes to security. People have been throwing fuzzers at it for as long as I remember and coming back with a nearly inexhaustible supply of memory corruption bugs. Here's an effort by one Googler a decade ago:
So, while it's a demo of the capabilities of LLMs, this should not be at all surprising. Ffmpeg is absolutely not something you should be running outside of a sandbox if you're touching any untrusted or user-supplied content. I know that people do, and these people are taking unreasonable risks.
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.
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?
Some of the ffmpeg developers were on Lex Fridman's podcast recently, and the topic of security came up.
They were talking about how there was a vulnerability in an extremely niche codec that is only used for one video game from the 90s or something, and were saying that the person who reported the vulnerability was acting like it was a big deal but it's really not because this codec is hardly ever used.
I was left wondering whether they were oblivious to the fact that an attacker who can supply a video file to you is free to use whatever video codec they want? It wouldn't matter if the developers thought the codec was never used at all; if it is still available then an attacker can use it.
Or was I just missing something? Is there a good reason why vulnerabilities in this codec are not a big deal after all?
The user is not free to use whatever codec they want. Many niche codecs can't be put into the usual containers, so if you only accept QuickTime/MP4 and AVI, sometimes even just by limiting the file extension, those codecs can't be used.
If your service works by taking whatever file the user gives you and shoving it into unsandboxed ffmpeg, you've already fucked up. It would be nice if you could do that, but that's not a guarantee ffmpeg has ever provided, nor would it make sense for them to spend their limited resources on it.
Is it really available in practice ? Eg. do major distros even compile ffmpeg with these obscure codecs or you need to recompile it yourself to get it ?
Big pipeline fat data users of ffmpeg can and do build their own executables that only include the top N codecs, that eliminates minor bug in obscure never used format problems pretty thoroughly.
while sandboxing ffmpeg directly isn't difficult, unfortunately with something like MPV/VLC that uses ffmpeg it's more challenging. until recently (virtio gpu native context) it wasn't even possible to sandbox a video player without losing all hardware acceleration. at least not from the outside, they could always try to sequester ffmpeg and seccomp it to hell like chromium.
There's certainly assembly that maps directly to the machine language bytes, I assume you are talking about the version of assembly with the high level loop macros
Apr Fools Day really is the shittiest day to be online. For one thing, practical jokes/pranks are just gussied-up asshole behavior. For another thing, nerds generally SUCK at information-delivery pranks, which is what the Internet is full of on Apr 1.
Back in 2004 when free email services like hotmail were limited to 10-15mb, on April 1st the evening standard front page headline, which I saw in the office around 2pm, was something âGoogle lunched 1gb emailâ
I couldnât believe they had fallen for an April fools so hard.
I don't have an example, but I know the pattern. You are working on your software, security researcher finds a bug, it's in your project, for you it's just another bug, but for them it's a point on their CV, so they make a theater about it, and expect priority in dealing with it. It must get tiring if you get many of these.
One dude running an X account is not indicative of a community to be honest.
That said, that dude has a point. "Researchers" chasing clout with their names attached to CVEs is kind of ridiculous. Half these CVEs are missing bounds checks that can be fixed with a patch in as much effort as writing up the blog post announcing that there was a missing bounds check.
The majority of code in ffmpeg today isn't written by Fabrice, but also there's multiple axes that people view programming ability on. Some people can write software that will do things you couldn't imagine given the constraints. Some people can write software that is resilient against all malformed input. Sometimes these people are the same people, but frequently they're not.
Can't help laughing at a random ad hominem against John Carmack of all people, and about his opinion on a guy who is already widely regarded as an especially talented programmer.
I don't think that's fair. There's a lot of talent and grit behind ffmpeg. But for better or worse, getting the code to do what it's supposed to do requires a different mindset than getting it to not do anything else (i.e., to handle malicious inputs correctly).
The developers of ffmpeg are very good at the first thing and not very good at the second. But few people on this planet, if instructed to write a complex video format parser in C or assembly, can produce something that's secure on the first try. The main failing of the ffmpeg team is that they should have spent more time on architectural hardening and mitigations. Most other large projects of this type do.
My understanding is that ffmpeg is probably incredibly close to the metal, with tons of assembler mixed in. I imagine doing the same in Rust would include lots of `unsafe` blocks and a similar amount of assembly, so it wouldn't change much in terms of security. Or am I wrong?
If there was a nearly inexhaustible supply of Indian security researchers emailing you a nearly inexhaustible supply of LLM slop daily, there is a point where you or I would stop caring too.
ffmpeg is Free Software. You are also free not to use it.
Oddly enough, despite all these endless grievances, no one has come up with a better or more capable tool, certainly not one that is freely available.
Evidently no one cares either, because most implementations of ffmpeg I've seen typically run it as root "because we have to". Don't worry we use Docker bro.
> AI slop is a real problem and annoying. Just because it exists does not mean every vulnerability report is AI slop.
Ok but who is going to sift through it all to triage the good bits when you're working on something for free?
> Ffmpeg devs are free not to care, but then they cant complain when they start to get a bad reputation
Who gives a shit about reputation when you're the only game in town?
There is nothing out there that even attempts to approximate an ffmpeg clone. They are the Swiss army knife of media encoding and all complainers have produced are plastic sporks.
> Ok but who is going to sift through it all to triage the good bits when you're working on something for free?
Its like anything else in open source. Maintainers will do so if they care. Maybe they decide they don't care. That is always their decision to make but there are consequences for the project. Maybe those consequences make sense. Being a maintainer is all about making cost-benefit trade offs.
> Who gives a shit about reputation when you're the only game in town?
Its up to the maintainers whether they care or not. It depends on what they value.
Ultimately if maintainers make decisions that are at odds with what their userbase want, someone eventually forks and people vote with their feet.
Today it's an industry driven by unscrupulous clout-chasers and a commitment to quantity over quality.
There is a difference between going through patches and pull requests vs. the endless stream of LLM-assisted bullshit that has started cluttering security inboxes in the last few years.
> Yes, and people will sit there and sip tea while waiting for "someone"? For how long?
Until someone cares enough to do it. This is open source software. When it comes to open source, the golden rule is you either do the things you care about yourself or stfu.
Given the libav fork wasn't all that long ago, it can obviously happen to ffmpeg just as much as it can happen to any other project.
Gstreamer is a multimedia framework where the user creates media DAGs by placing video/audio/multimedia elements such as demuxers, decoders etc in a pipeline. The framework then takes care of running the media pipeline and handles the data buffering etc.
Within the framework there are multitudes of plugin packages that contain said elements and many of them are built on top of ffmpeg.
Any multimedia project trying to support a large number of formats, whose usage in the wild differs by orders of magnitude, is going to have code of varying quality (although quality is not strictly correlated with usage: age and complexity are also big factors, among others). GStreamer puts plugins into different categories (-good, -bad, etc.) based on things like the maturity of the code, which helps you judge what risks you are taking. With FFmpeg it is harder to know which formats are more likely to have issues. Of course GStreamer can use FFmpeg, in which case you will also have all of FFmpeg's problems.
In both cases you are best off restricting things to what you actually use.
From what I understand gstreamer is more about building complex pipelines and plugins, ffmpeg is better at playing some obscure 20 year old video format extremely efficiently so you can watch it compiled for a potato.
That's not really true. Ffmpeg is a Swiss army knife for anything related to digital multimedia (old and new). It is broken into a few libraries but doesn't really have plugins.
Gstreamer has a different model, chaining together plugins. Lots of overlap, but I think Gstreamer only has real traction because some silicon vendors use it.
GStreamer doesnât use ffmpegâs pipeline at all. It implements a much more advanced directed graph with disconnect, connection and pad negotiation. You can dynamically swap out the entire filter graph during live playback with zero disruption. Swap feeds, outputs, effects⌠all at runtime.
ffmpeg and other media frameworks (Windows Media Foundation, Appleâs AVFramwork) only support static pipelines. You can use âswitcherâ components but the inputs are still static.
GStreamer is extremely special. The only thing that comes close was Microsoftâs DirectShow, which has since been replaced with Media Foundation which canât do it. And while DirectShow did support it, it was fragile because many 3rd party filters did not support dynamic configuration.
GStreamer does use ffmpeg, but it just wraps the core encoder/decoder/filter code and discards the streams/graph/pipe part of ffmpeg.
I completely agree, with regard for the GP's point about Android TV's with onboard ffmpeg libraries and Addon Apps that call on said libraries (or pull in their own) ..
Cheap arse low resource TVs should either include some form of sandboxing OR the entire device should be treated as a "can fall over" sandbox .. well isolated from any household LAN of consequence, etc.
It seems unlikely that BoxStore Brand Android TVs will be well designed with an eye to security so <shrug> they're an exercise for home net admin masochists and/or an opportunity to market sensible easy to use IoT age routers that come preconfigured to handle bad-device(s).
Am I getting this right, you expect TVs which are running Google TV (Android TV is the old name) to be less secure than TVs which are running a different operating system? I think the opposite is the case, because Google TV is developed by Google, which has a lot of experience with software security, while other TV operating systems are developed by companies which clearly don't have that experience.
The obvious question is, how many of those were the sort that writing in a memory-safe language would make impossible?
They should prompt one of the more adventurous LLMs to find security bugs and with some luck it will deviate from the prompt and rewrite ffmpeg in Rust.
Rewriting ffmpeg in Rust will not solve it. The parts that are memory unsafe in ffmpeg, and similar projects, are not unsafe because C or C++ is inherently unsafe. Instead, it's the CODE that is unsafe. Translating the code (data structures, logic, etc) to Rust does not fix bugs in the code. That code will be littered with "unsafe" code, and of course, it will no longer be maintainable.
I think the industry is optimizing for the wrong thing. Generating thousands of AI-written bug reports is easy, at least with Mythos (preview 1) or GPT-5.5. Getting bugs fixed is the hard part.
A few months ago I started working on a system that finds critical security issues and opens PRs instead of just filing reports. The acceptance rate is sitting at roughly 94% so far. Most of the failures were due to project-specific kill switches or other internal mechanisms that werenât documented, not because the vulnerability itself was misidentified.
Developers generally seem to prefer this approach. A bug report creates work. A good PR removes work. That sounds obvious, but a lot of security products still stop at the report and call it a day.
> I think the industry is optimizing for the wrong thing.
Indeed: The industry optimizes for speed, time to market, and features, and applies the ostrich model to everything that doesn't bring short-time revenue (security considerations, accessibility, vendor lock-in, interoperability, âŚ)
This has been going on for as long as the industry exists, and now we start to have the proper tools to assess the damage and understand the brittleness of it all.
>The reach of this bug is what makes it serious. Any deployment that points FFmpeg at an attacker-influenced RTSP URL is exposed: media ingest pipelines fetching user-supplied stream URLs, surveillance and CCTV systems pulling RTSP feeds, and transcoding services processing remote AV1-over-RTP sources
Wow this is actually pretty serious - I'm even surprised its being published. There are several services where I can imagine this is exploitable today.
Some people might suggest itâs crucial to publish if youâre aware of a serious vulnerability, so that people using the software in a vulnerable way can take steps to mitigate the risk.
Speed and security are not good bedfellows. Combine that with really shitty standards and dozens of years of development...
Oh, and licensing. Licensing is the real killer. I could just write my own mp3 decoder easily (the format not the file type) but I'm not gonna risk my company getting sued into the ground by doing that.
I donât think this is necessarily true! Constraints can be liberating: a language that allows strong encoding of invariants makes it easier for the languageâs compiler to optimize.
I agree about long periods of development and difficult standards, though.
Even if this isn't as big a deal as this [advertisement for a security company] seems, it is a reminder that every application you release does have a security hole somewhere, and a script kiddie can now find it 5 minutes after release for $2 in credit. If you're not red-teaming your code before release, hackers are doing it after.
Inflated use of the term zero-day, while none of the described vulnerabilities is actually a zero-day. But it sounds and clicks good..
thank you for the PoC.
> At this point the corrupted free pointer is called, and control of the instruction pointer is ours.
Very serious, though in practice it doesn't sound like this bug achieves arbitrary RCE on its own (especially in the presence of ASLR). You would need there to be some writable and executable page of memory lying around.
The article glosses over this, but it looks like the next variable in the struct is conveniently the first parameter to the function, so you can run arbitrary code with system() or whatever. But, yeah, you would need some other exploit to defeat ASLR.
If a security bug is exploited in the wild, it's an n-day if it's been first exploited n days after the publication of the bug, and a zero-day if it's been exploited before or on the day of the publication.
When a bug is not yet exploited in the wild, it's just a discovery of a bug, not a zero-day.
I understand why it's poorly understood. It's a snappy term, and people assume it means "bad" and nothing else because that's all you can get from the context. However, since most people also don't know the difference between a vulnerability and an exploit, they won't understand the definition of a zero-day when they read it.
But I'm still going to complain if a security vulnerability research company is using the term incorrectly in their own press copy. It makes them look amateurish.
No, that's the difference between exploit (knife) and either the incident or impact (wound). The vulnerability would be a gap in armor.
The vulnerability is the exposed weakness. Vulnerabilities get fixes, and they exist without anybody knowing about them. Vulnerabilities get CVEs assigned to them.
The exploit is the means of attack. It's the specific actions or calls that let you take advantage of a vulnerability. It could be a worm, or botnet scripts, or specifically crafted data[0]. A proof of concept is not an exploit itself, but it demonstrates that the vulnerability can be exploited.
An example of a vulnerability might be a gate where the gap between the door and the jam are too wide. The exploit is a coat hanger used to lift the inside latch from outside the gate. That results in unprivileged access.
And zero-day specifically compares when the white hats (vendors, system owners) and the black hats learn about the existence of a vulnerability. If white hats learn that a vulnerability exists by being subject to an in-the-wild black hat exploit of it, then it's a true zero-day.
I've been using ffmpeg for a very long time, both personally and for services I've built. Fabrice Bellard is a genius, and the developers who have taken it so far have made the world measurably richer.
But I can't think of a program more worthy of sandboxing when run with untrusted input than ffmpeg. It's a huge amount of C dealing with the most complicated video and audio codecs, which is notoriously impossible to get completely right.
But it's not actually that big of a problem. I run ffmpeg inside a VM or gVisor, and the end result is usually a video file that I'm perfectly willing to play in my browser, where it gets decoded in yet another sandbox because this shit is hard.
What do you mean "video file that I'm perfectly willing to play in my browser". Isn't it safe to assume that no video file can escape the browser decoding sandbox?
I'm not up-to-speed with the current state of sandboxing in browsers, but in principle it's (on modern operating systems) not especially hard for them to sandbox the decoding into a separate process with basically no privileges beyond rendering a video stream. It's a bit trickier if we're only considering demuxing and delegating decoding to the hardware, but that's a much smaller attack surface.
A manually run ffmpeg on the command line does nothing to restrict its privileges, and its security model has very little interest in doing so, while browsers very much have.
Is the future of defense-against-foreign-agents-on-my-codebase to subtly hide prompt injections into oneâs codebase that would defeat agents to find security bugs ?
If the attackers of ffmpeg need to be using such those authorsâ services to find RCE in popular tools to attack, what the ffmpeg team needs to defeat attackers is to reduce efficiency of such tools depthfirst
Most of them involve very weird and unlikely scenarios and bad security practices or access to the ffmpeg binaries and being allowed to run arbitrary commands at an elevated permission.
In and of itself there's not a massive issue from what I can see, they're entry vectors that can lead to worse situations.
That's not to say they're not serious but if a Russian hacking group is using one of them it's in conjunction with other exploits or security flaws. Which is common in practice when it comes to decoding.
What about VLC's own built-in versions of decoding libraries (I think, from the FFmpeg project)? Is there a scenario here where we may have to deal with malicious MP4 files?
Help me understand: depthfirst seems to be bigging up their âsecurity agentâ here, but is it not just prompt engineering + writing skill files? What goes into producing a âsecurity agentâ beyond this? Feels like theyâre really gussying up a process that is ultimately just LLM usage
I just had an unsettling thought⌠those with access to Mythos/Fable finding these flaws â how many might be holding back and keeping some of these exploits in their back pocket?
For executables on Linux there are things like bubblewrap or firejail. One can also use a restrictive container. But those are strictly weaker than browser sandboxes.
The most secure way presently is to use qubes-os that allows to use a very hardened VM to run individual applications.
"No way to prevent this" say users of only language where this regularly happens, etc, etc. Several of these bugs do not appear to be in hot code and would have been detected by a language with saner behaviour.
Ffmpeg has an exceptionally terrible track record when it comes to security. People have been throwing fuzzers at it for as long as I remember and coming back with a nearly inexhaustible supply of memory corruption bugs. Here's an effort by one Googler a decade ago:
https://security.googleblog.com/2014/01/ffmpeg-and-thousand-...
So, while it's a demo of the capabilities of LLMs, this should not be at all surprising. Ffmpeg is absolutely not something you should be running outside of a sandbox if you're touching any untrusted or user-supplied content. I know that people do, and these people are taking unreasonable risks.
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.
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?
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
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. Itâs not a major risk.
Some of the ffmpeg developers were on Lex Fridman's podcast recently, and the topic of security came up.
They were talking about how there was a vulnerability in an extremely niche codec that is only used for one video game from the 90s or something, and were saying that the person who reported the vulnerability was acting like it was a big deal but it's really not because this codec is hardly ever used.
I was left wondering whether they were oblivious to the fact that an attacker who can supply a video file to you is free to use whatever video codec they want? It wouldn't matter if the developers thought the codec was never used at all; if it is still available then an attacker can use it.
Or was I just missing something? Is there a good reason why vulnerabilities in this codec are not a big deal after all?
The user is not free to use whatever codec they want. Many niche codecs can't be put into the usual containers, so if you only accept QuickTime/MP4 and AVI, sometimes even just by limiting the file extension, those codecs can't be used.
If your service works by taking whatever file the user gives you and shoving it into unsandboxed ffmpeg, you've already fucked up. It would be nice if you could do that, but that's not a guarantee ffmpeg has ever provided, nor would it make sense for them to spend their limited resources on it.
Is it really available in practice ? Eg. do major distros even compile ffmpeg with these obscure codecs or you need to recompile it yourself to get it ?
Big pipeline fat data users of ffmpeg can and do build their own executables that only include the top N codecs, that eliminates minor bug in obscure never used format problems pretty thoroughly.
while sandboxing ffmpeg directly isn't difficult, unfortunately with something like MPV/VLC that uses ffmpeg it's more challenging. until recently (virtio gpu native context) it wasn't even possible to sandbox a video player without losing all hardware acceleration. at least not from the outside, they could always try to sequester ffmpeg and seccomp it to hell like chromium.
Of course. Everybody knows to rather use the obvious alternative to ffmpeg!
They're also extremely hostile to security researchers who report these issues.
https://x.com/ffmpeg/status/2039115531744334180?s=46&t=qCSkw...
Security is the punch line for ffmpeg.
I'm glad to see their sense of humour :-)
https://nitter.net/ffmpeg/status/2039115531744334180
> Assembly is a human readable version of machine code. It's exactly the same.
goddamn, and this is a project that prides itself on having had-written assembly in it
There's certainly assembly that maps directly to the machine language bytes, I assume you are talking about the version of assembly with the high level loop macros
In some circles, High Level Assembly (HLA) is lovingly called "Mainframe Assembly".
Oh my god! They are so funny and memeable! gets RCE'd
Apr Fools Day really is the shittiest day to be online. For one thing, practical jokes/pranks are just gussied-up asshole behavior. For another thing, nerds generally SUCK at information-delivery pranks, which is what the Internet is full of on Apr 1.
Back in 2004 when free email services like hotmail were limited to 10-15mb, on April 1st the evening standard front page headline, which I saw in the office around 2pm, was something âGoogle lunched 1gb emailâ
I couldnât believe they had fallen for an April fools so hard.
In their defense, the "rewrite it in rust" crowd can be really grating.
The guy running the twitter account is incompetent but the actual devs are a lot saner I think.
I agree it reflects poorly on them though
> ⌠hostile to security researchers who report these issues.
Do you have an example?
I don't have an example, but I know the pattern. You are working on your software, security researcher finds a bug, it's in your project, for you it's just another bug, but for them it's a point on their CV, so they make a theater about it, and expect priority in dealing with it. It must get tiring if you get many of these.
I have numerous examples of security researchers being hostile and impossible to work with (but cannot share them unfortunately).
One dude running an X account is not indicative of a community to be honest.
That said, that dude has a point. "Researchers" chasing clout with their names attached to CVEs is kind of ridiculous. Half these CVEs are missing bounds checks that can be fixed with a patch in as much effort as writing up the blog post announcing that there was a missing bounds check.
I guess that the perceived problem from a security perspective is that they're there, not that they're necessarily hard to fix once found.
Funny, John Carmack was just admiring the creator of ffmpeg the other day for being a better programmer. https://x.com/id_aa_carmack/status/2064095424420487226?s=46
The majority of code in ffmpeg today isn't written by Fabrice, but also there's multiple axes that people view programming ability on. Some people can write software that will do things you couldn't imagine given the constraints. Some people can write software that is resilient against all malformed input. Sometimes these people are the same people, but frequently they're not.
One thing has nothing to do with the other.
Security vulnerabilities are less about programming ability and more about rigor.
Famous man whose last impactful work was decades ago and spent years on meta's sinking metaverse boat said so, so it must be true.
Can't help laughing at a random ad hominem against John Carmack of all people, and about his opinion on a guy who is already widely regarded as an especially talented programmer.
I don't think that's fair. There's a lot of talent and grit behind ffmpeg. But for better or worse, getting the code to do what it's supposed to do requires a different mindset than getting it to not do anything else (i.e., to handle malicious inputs correctly).
The developers of ffmpeg are very good at the first thing and not very good at the second. But few people on this planet, if instructed to write a complex video format parser in C or assembly, can produce something that's secure on the first try. The main failing of the ffmpeg team is that they should have spent more time on architectural hardening and mitigations. Most other large projects of this type do.
So all I am hearing is.. Rust
My understanding is that ffmpeg is probably incredibly close to the metal, with tons of assembler mixed in. I imagine doing the same in Rust would include lots of `unsafe` blocks and a similar amount of assembly, so it wouldn't change much in terms of security. Or am I wrong?
So who is someone who's opinion is worth anything to you?
Except yourself, presumably, to me it almost seems nobody is perfect.
On this subject I'd at minimum expect someone with experience in security. Not someone most famously known for making toys that run on computers.
I've seen a lot of things written about Carmack over the last 30+ years, not one comment this casually dismissive until today.
If there was a nearly inexhaustible supply of Indian security researchers emailing you a nearly inexhaustible supply of LLM slop daily, there is a point where you or I would stop caring too.
ffmpeg is Free Software. You are also free not to use it.
Oddly enough, despite all these endless grievances, no one has come up with a better or more capable tool, certainly not one that is freely available.
Evidently no one cares either, because most implementations of ffmpeg I've seen typically run it as root "because we have to". Don't worry we use Docker bro.
> nearly inexhaustible supply of LLM slop daily,
Actual well written vulnerability reports are not the same as slop.
AI slop is a real problem and annoying. Just because it exists does not mean every vulnerability report is AI slop.
Ffmpeg devs are free not to care, but then they cant complain when they start to get a bad reputation.
> AI slop is a real problem and annoying. Just because it exists does not mean every vulnerability report is AI slop.
Ok but who is going to sift through it all to triage the good bits when you're working on something for free?
> Ffmpeg devs are free not to care, but then they cant complain when they start to get a bad reputation
Who gives a shit about reputation when you're the only game in town?
There is nothing out there that even attempts to approximate an ffmpeg clone. They are the Swiss army knife of media encoding and all complainers have produced are plastic sporks.
> Ok but who is going to sift through it all to triage the good bits when you're working on something for free?
Its like anything else in open source. Maintainers will do so if they care. Maybe they decide they don't care. That is always their decision to make but there are consequences for the project. Maybe those consequences make sense. Being a maintainer is all about making cost-benefit trade offs.
> Who gives a shit about reputation when you're the only game in town?
Its up to the maintainers whether they care or not. It depends on what they value.
Ultimately if maintainers make decisions that are at odds with what their userbase want, someone eventually forks and people vote with their feet.
Security is a bit different.
Today it's an industry driven by unscrupulous clout-chasers and a commitment to quantity over quality.
There is a difference between going through patches and pull requests vs. the endless stream of LLM-assisted bullshit that has started cluttering security inboxes in the last few years.
Vulnerability researchers don't create the vulnerabilities they report. The vulnerabilities exist whether or not they're reported by "clout chasers".
Yes, and people will sit there and sip tea while waiting for "someone"? For how long?
> Yes, and people will sit there and sip tea while waiting for "someone"? For how long?
Until someone cares enough to do it. This is open source software. When it comes to open source, the golden rule is you either do the things you care about yourself or stfu.
Given the libav fork wasn't all that long ago, it can obviously happen to ffmpeg just as much as it can happen to any other project.
Is GStreamer a more secure alternative or does it just get a bit less attention than ffmpeg?
Gstreamer is a multimedia framework where the user creates media DAGs by placing video/audio/multimedia elements such as demuxers, decoders etc in a pipeline. The framework then takes care of running the media pipeline and handles the data buffering etc.
Within the framework there are multitudes of plugin packages that contain said elements and many of them are built on top of ffmpeg.
Any multimedia project trying to support a large number of formats, whose usage in the wild differs by orders of magnitude, is going to have code of varying quality (although quality is not strictly correlated with usage: age and complexity are also big factors, among others). GStreamer puts plugins into different categories (-good, -bad, etc.) based on things like the maturity of the code, which helps you judge what risks you are taking. With FFmpeg it is harder to know which formats are more likely to have issues. Of course GStreamer can use FFmpeg, in which case you will also have all of FFmpeg's problems.
In both cases you are best off restricting things to what you actually use.
From what I understand gstreamer is more about building complex pipelines and plugins, ffmpeg is better at playing some obscure 20 year old video format extremely efficiently so you can watch it compiled for a potato.
Different cases really I think both are good.
That's not really true. Ffmpeg is a Swiss army knife for anything related to digital multimedia (old and new). It is broken into a few libraries but doesn't really have plugins.
Gstreamer has a different model, chaining together plugins. Lots of overlap, but I think Gstreamer only has real traction because some silicon vendors use it.
GStreamer is just a different front end to ffmpeg.
ffmpeg's core functionality (encode, decode, streams, pipes, channels) are all implemented in `libav` which gstreamer links against.
GStreamer doesnât use ffmpegâs pipeline at all. It implements a much more advanced directed graph with disconnect, connection and pad negotiation. You can dynamically swap out the entire filter graph during live playback with zero disruption. Swap feeds, outputs, effects⌠all at runtime.
ffmpeg and other media frameworks (Windows Media Foundation, Appleâs AVFramwork) only support static pipelines. You can use âswitcherâ components but the inputs are still static.
GStreamer is extremely special. The only thing that comes close was Microsoftâs DirectShow, which has since been replaced with Media Foundation which canât do it. And while DirectShow did support it, it was fragile because many 3rd party filters did not support dynamic configuration.
GStreamer does use ffmpeg, but it just wraps the core encoder/decoder/filter code and discards the streams/graph/pipe part of ffmpeg.
> ffmpeg and other media frameworks (Windows Media Foundation, Appleâs AVFramwork) only support static pipelines.
FFmpeg doesn't do âpipelinesâ. It's a library, not a framework.
Doesn't GStreamer mostly use ffmpeg plugins?
In my experience it's mainly run by very grumpy and opinionated Europeans who take pride in having bugs old enough to drink.
Time to RIIR, then?
I haven't seen that acronym before, but my guess is that it's "Re-Implement In Rust", right?
Usually it's Rewrite it in Rust, but both work I guess
Doesn't this negate all the amazing muh assembly hacking that they do lol
> Ffmpeg is absolutely not something you should be running outside of a sandbox if you're touching any untrusted or user-supplied content.
You would change your opinion quickly if your browser, apps and TV suddenly stopped supporting videos due to relying on FFmpeg.
What prevents running a data stream in, transcoded data out sandbox with no access to unlimited resources, system files, system stacks, etc.
It's okay for a sandbox to fall over due to bad inputs and poor memory security if it can just be restarted and move onto other streams.
I think Chromium already does sandbox ffmpeg in the renderer process because of their "Rule of Two": https://chromium.googlesource.com/chromium/src/+/HEAD/docs/s...
Thus:
1. Code which processes untrusted input
2. Code written in unsafe languages like C or C++
3. Code that runs without a sandbox
So ffmpeg should be sandboxed, same as the network code and GPU process are sandboxed.
I completely agree, with regard for the GP's point about Android TV's with onboard ffmpeg libraries and Addon Apps that call on said libraries (or pull in their own) ..
Cheap arse low resource TVs should either include some form of sandboxing OR the entire device should be treated as a "can fall over" sandbox .. well isolated from any household LAN of consequence, etc.
It seems unlikely that BoxStore Brand Android TVs will be well designed with an eye to security so <shrug> they're an exercise for home net admin masochists and/or an opportunity to market sensible easy to use IoT age routers that come preconfigured to handle bad-device(s).
Am I getting this right, you expect TVs which are running Google TV (Android TV is the old name) to be less secure than TVs which are running a different operating system? I think the opposite is the case, because Google TV is developed by Google, which has a lot of experience with software security, while other TV operating systems are developed by companies which clearly don't have that experience.
There are a lot of "Android like" TVs out there.
Those are running mainly on Google TV. Tizen or webOS are also common but are not based on Android.
ffmpeg is also rather popular and delivers a lot of functionality. Its unlikely that you don't have it installed.
Yes, there are security issues but quite a few are not ffmpeg itself related - the input is pretty shabby or at least not exactly easy to deal with!
Obviously, they could do with some assistance and I'm sure you and I will both dive in with equal zeal.
The obvious question is, how many of those were the sort that writing in a memory-safe language would make impossible?
They should prompt one of the more adventurous LLMs to find security bugs and with some luck it will deviate from the prompt and rewrite ffmpeg in Rust.
Rewriting ffmpeg in Rust will not solve it. The parts that are memory unsafe in ffmpeg, and similar projects, are not unsafe because C or C++ is inherently unsafe. Instead, it's the CODE that is unsafe. Translating the code (data structures, logic, etc) to Rust does not fix bugs in the code. That code will be littered with "unsafe" code, and of course, it will no longer be maintainable.
I think the industry is optimizing for the wrong thing. Generating thousands of AI-written bug reports is easy, at least with Mythos (preview 1) or GPT-5.5. Getting bugs fixed is the hard part.
A few months ago I started working on a system that finds critical security issues and opens PRs instead of just filing reports. The acceptance rate is sitting at roughly 94% so far. Most of the failures were due to project-specific kill switches or other internal mechanisms that werenât documented, not because the vulnerability itself was misidentified.
Developers generally seem to prefer this approach. A bug report creates work. A good PR removes work. That sounds obvious, but a lot of security products still stop at the report and call it a day.
I think I'm missing something here. Apple software has no open source code, how are you suggesting fixes?
What?
https://github.com/apple
I genuinely didn't know about their OSS efforts, thanks!
I wouldn't go so far as efforts, so much as legally required publication of 3rd party code they use, or open wrappers to their proprietary libraries
> I think the industry is optimizing for the wrong thing.
Indeed: The industry optimizes for speed, time to market, and features, and applies the ostrich model to everything that doesn't bring short-time revenue (security considerations, accessibility, vendor lock-in, interoperability, âŚ)
This has been going on for as long as the industry exists, and now we start to have the proper tools to assess the damage and understand the brittleness of it all.
>The reach of this bug is what makes it serious. Any deployment that points FFmpeg at an attacker-influenced RTSP URL is exposed: media ingest pipelines fetching user-supplied stream URLs, surveillance and CCTV systems pulling RTSP feeds, and transcoding services processing remote AV1-over-RTP sources
Wow this is actually pretty serious - I'm even surprised its being published. There are several services where I can imagine this is exploitable today.
Some people might suggest itâs crucial to publish if youâre aware of a serious vulnerability, so that people using the software in a vulnerable way can take steps to mitigate the risk.
You would also need some sort of ASLR leak to make this exploitable
Speaking from firsthand experience: codec and other media processing libraries are some of the easiest software to find address leaks in.
(There are a number of reasons for this, not least being that C makes it very easy to ship partially initialized memory over the wire.)
Speed and security are not good bedfellows. Combine that with really shitty standards and dozens of years of development...
Oh, and licensing. Licensing is the real killer. I could just write my own mp3 decoder easily (the format not the file type) but I'm not gonna risk my company getting sued into the ground by doing that.
I donât think this is necessarily true! Constraints can be liberating: a language that allows strong encoding of invariants makes it easier for the languageâs compiler to optimize.
I agree about long periods of development and difficult standards, though.
ffmpeg has stated many many times that they don't care about bug or security reports
Even if this isn't as big a deal as this [advertisement for a security company] seems, it is a reminder that every application you release does have a security hole somewhere, and a script kiddie can now find it 5 minutes after release for $2 in credit. If you're not red-teaming your code before release, hackers are doing it after.
Inflated use of the term zero-day, while none of the described vulnerabilities is actually a zero-day. But it sounds and clicks good.. thank you for the PoC.
> At this point the corrupted free pointer is called, and control of the instruction pointer is ours.
Very serious, though in practice it doesn't sound like this bug achieves arbitrary RCE on its own (especially in the presence of ASLR). You would need there to be some writable and executable page of memory lying around.
The article glosses over this, but it looks like the next variable in the struct is conveniently the first parameter to the function, so you can run arbitrary code with system() or whatever. But, yeah, you would need some other exploit to defeat ASLR.
That's not what "zero-day" means.
Explain what it means along with your statement. Maybe I have the wrong definition too.
(not op)
If a security bug is exploited in the wild, it's an n-day if it's been first exploited n days after the publication of the bug, and a zero-day if it's been exploited before or on the day of the publication.
When a bug is not yet exploited in the wild, it's just a discovery of a bug, not a zero-day.
It seems to have lost its meaning after getting popularized following Stuxnet coverage.
No, I think it was since Code Red.
I understand why it's poorly understood. It's a snappy term, and people assume it means "bad" and nothing else because that's all you can get from the context. However, since most people also don't know the difference between a vulnerability and an exploit, they won't understand the definition of a zero-day when they read it.
But I'm still going to complain if a security vulnerability research company is using the term incorrectly in their own press copy. It makes them look amateurish.
> the difference between a vulnerability and an exploit
is it the difference between a knife and a stab wound?
No, that's the difference between exploit (knife) and either the incident or impact (wound). The vulnerability would be a gap in armor.
The vulnerability is the exposed weakness. Vulnerabilities get fixes, and they exist without anybody knowing about them. Vulnerabilities get CVEs assigned to them.
The exploit is the means of attack. It's the specific actions or calls that let you take advantage of a vulnerability. It could be a worm, or botnet scripts, or specifically crafted data[0]. A proof of concept is not an exploit itself, but it demonstrates that the vulnerability can be exploited.
An example of a vulnerability might be a gate where the gap between the door and the jam are too wide. The exploit is a coat hanger used to lift the inside latch from outside the gate. That results in unprivileged access.
And zero-day specifically compares when the white hats (vendors, system owners) and the black hats learn about the existence of a vulnerability. If white hats learn that a vulnerability exists by being subject to an in-the-wild black hat exploit of it, then it's a true zero-day.
[0]: https://xkcd.com/327/
I've been using ffmpeg for a very long time, both personally and for services I've built. Fabrice Bellard is a genius, and the developers who have taken it so far have made the world measurably richer.
But I can't think of a program more worthy of sandboxing when run with untrusted input than ffmpeg. It's a huge amount of C dealing with the most complicated video and audio codecs, which is notoriously impossible to get completely right.
But it's not actually that big of a problem. I run ffmpeg inside a VM or gVisor, and the end result is usually a video file that I'm perfectly willing to play in my browser, where it gets decoded in yet another sandbox because this shit is hard.
I glumly predict that copyright-holding companies wanting DRM, "trusted platforms", regulatory capture, etc. will drive some of the damage here.
Secure sandboxing tends to mean opportunities to make unrestricted copies.
What do you mean "video file that I'm perfectly willing to play in my browser". Isn't it safe to assume that no video file can escape the browser decoding sandbox?
Isn't it safe to assume that no video file can escape the browser decoding sandbox?
It's 'safe to assume' it's not. It's emphatically not safe to assume any mitigation is perfect.
> Isn't it safe to assume that no video file can escape the browser decoding sandbox?
Why would that be safe to assume? If that were a reasonable assumption, you could just as well assume that it's safe to run ffmpeg.
I'm not up-to-speed with the current state of sandboxing in browsers, but in principle it's (on modern operating systems) not especially hard for them to sandbox the decoding into a separate process with basically no privileges beyond rendering a video stream. It's a bit trickier if we're only considering demuxing and delegating decoding to the hardware, but that's a much smaller attack surface.
A manually run ffmpeg on the command line does nothing to restrict its privileges, and its security model has very little interest in doing so, while browsers very much have.
Yeah, then you need to stream content in real time between multiple processes. And not screw up the licensing.
And get hardware acceleration working...
The parent does argues it is safer to sandbox ffmpeg yes
But then you also often need hardware accelerators for encoding, so you need to use C again.
Is the future of defense-against-foreign-agents-on-my-codebase to subtly hide prompt injections into oneâs codebase that would defeat agents to find security bugs ?
If the attackers of ffmpeg need to be using such those authorsâ services to find RCE in popular tools to attack, what the ffmpeg team needs to defeat attackers is to reduce efficiency of such tools depthfirst
No...
I find difficult to know how serious the issue is, if it is even an issue.
LLM constantly confidently giving me this same sounding script with a "the root cause" and how it "is simple" while being completely incorrect.
Most of them involve very weird and unlikely scenarios and bad security practices or access to the ffmpeg binaries and being allowed to run arbitrary commands at an elevated permission.
In and of itself there's not a massive issue from what I can see, they're entry vectors that can lead to worse situations.
That's not to say they're not serious but if a Russian hacking group is using one of them it's in conjunction with other exploits or security flaws. Which is common in practice when it comes to decoding.
Its 21 issues. And they've been human validated, as far as I can tell.
What about VLC's own built-in versions of decoding libraries (I think, from the FFmpeg project)? Is there a scenario here where we may have to deal with malicious MP4 files?
All media containers are potentially hostile. Any offset, extent, or reference has to be considered hostile user-provided input.
Help me understand: depthfirst seems to be bigging up their âsecurity agentâ here, but is it not just prompt engineering + writing skill files? What goes into producing a âsecurity agentâ beyond this? Feels like theyâre really gussying up a process that is ultimately just LLM usage
Is there a timeline for each of these bugs? I wonder if these bugs had been reported to ffmpeg yet.
I just had an unsettling thought⌠those with access to Mythos/Fable finding these flaws â how many might be holding back and keeping some of these exploits in their back pocket?
Infinity - 21 is still infinity
> A victim only has to run ffmpeg -i rtsp://attacker/stream, the most ordinary command imaginable
What about "ls"?
How does the browser use it ?unless they mean thereâs a zero day in libavcodec
Browsers run it in a sandbox process together with allocator hardening. Most of the bugs then are just crashed of the sandbox
Another option is WASM or WASM-style sandboxes if using another process is undesirable.
One chained sandbox escape away from compromise.
Ahah
But are the compiler+OS that runs the ffmpeg executable really a sandbox ?
For executables on Linux there are things like bubblewrap or firejail. One can also use a restrictive container. But those are strictly weaker than browser sandboxes.
The most secure way presently is to use qubes-os that allows to use a very hardened VM to run individual applications.
Which is of course better than zero sandbox escapes.
"No way to prevent this" say users of only language where this regularly happens, etc, etc. Several of these bugs do not appear to be in hot code and would have been detected by a language with saner behaviour.
Well, get to work then and rewrite, should be quick. Chop-chop!