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104 points trollied | 13 comments | | HN request time: 0s | source | bottom
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vqtska ◴[] No.45785720[source]
I wonder if this vulnerable codec is enabled by default when building FFmpeg? Because if so, then it doesn't matter that it's a "1990s game codec" because any application using FFmpeg to accept arbitrary video files is vulnerable to memory corruption, which should probably be taken more seriously.
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IshKebab ◴[] No.45786093[source]
I checked with Ubuntu's ffmpeg and it is enabled by default. There are a huge list of codecs enabled by default (maybe all of them?). Given the security track record of codecs implemented in C, this means it's basically guaranteed that there are dozens of security vulnerabilities in ffmpeg.

I think the same is probably true for VLC to a lesser extent, which is pretty wild considering I've never heard of it being used as an attack vector, e.g. via torrents.

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haskellshill ◴[] No.45786299[source]
VLC is pretty popular on windows, but ffmpeg? Is there any commonly used windows app that relies on it? I doubt it'd be worth one's time to write exploits for desktop linux
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dpe82 ◴[] No.45788108[source]
VLC and ffmpeg share the same underlying library family (libav*) where this vulnerability lives.

> I doubt it'd be worth one's time to write exploits for desktop Linux

How many developers, network administrators, etc. run desktop Linux? Gaining access to those can be very, very valuable.

replies(1): >>45788198 #
1. brigade ◴[] No.45788198[source]
FFmpeg based players have been popular for 20 years now. Has there been a single documented actual use of their libraries as the exploitation vector anytime in the last two decades?
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2. dpe82 ◴[] No.45788461[source]
I'm certain it's happened but since I don't have one off the top of my head I'll instead point out a related issue: https://en.wikipedia.org/wiki/Stagefright_(bug)

It's worth pointing out that many, many, many things use the libav* library family.

replies(1): >>45791047 #
3. dns_snek ◴[] No.45788771[source]
Does this count?

https://signal.org/blog/cellebrite-vulnerabilities/

> Given the number of opportunities present, we found that it’s possible to execute arbitrary code on a Cellebrite machine simply by including a specially formatted but otherwise innocuous file in any app on a device that is subsequently plugged into Cellebrite and scanned. There are virtually no limits on the code that can be executed.

But it was a product using a 9 year old ffmpeg build (at the time).

replies(2): >>45791209 #>>45791264 #
4. brigade ◴[] No.45791047[source]
Yes, I know that multimedia/image vulnerabilities are popular vectors for zero-click attacks. My point is that desktop players are not a vector for zero-click attacks, and ffmpeg has not generally been used in end-user situations that are targets of zero-click or drive-by attacks. Mostly because of the license, but still.

If the exploit chain involves the user downloading and opening a file, something like >99% of the time the next step already involves executable code (or Office macros), which makes any ffmpeg vuln completely useless.

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5. brigade ◴[] No.45791209[source]
I'd still consider that an academic exercise rather than an exploit that was deployed in the real world (aka against a machine the attacker did not control)
replies(1): >>45794162 #
6. hulitu ◴[] No.45791264[source]
> Does this count?

If Signal relies on ffmpeg to play videos instead of an externall app, i would say it is broken by design.

7. dpe82 ◴[] No.45792508{3}[source]
Chrome uses ffmpeg's underlying libraries.

It's used way, way more than you think.

replies(1): >>45793149 #
8. phil21 ◴[] No.45792826{3}[source]
In a past life as a managed hosting provider ffmpeg exploits were used to gain access to systems.

It’s used for pretty much any platform you can upload video to. Some places far more competently than others.

replies(1): >>45793164 #
9. brigade ◴[] No.45793149{4}[source]
Yes, I’m quite familiar with that. Chrome is why I added the “generally” qualifier.

And to the best of my knowledge, there has not been any in-the-wild exploit against Chrome through the handful of ffmpeg codecs they enable. Not even pwn2own type competitions either, as I recall.

replies(1): >>45794298 #
10. brigade ◴[] No.45793164{4}[source]
See, I’d be interested in any actual evidence/writeups of that in the wild.
replies(1): >>45795030 #
11. renewiltord ◴[] No.45794162{3}[source]
Yeah, that’s just how life is. We used to run with Heartbleed and Spectre turned off.
12. dpe82 ◴[] No.45794298{5}[source]
I guess I'm confused - are you trying to imply the lack of a thorough, publicly reported successful exploit (or us just not casually giving you one that you care about) means that we're all released from the responsibility of taking potential exploits seriously?
13. bawolff ◴[] No.45795030{5}[source]
In fairness, i dont think the majority of actual exploits used in the wild get writeups.

Budget web host using outdated software getting hacked because they havent updated in 2 years isn't exactly all that interesting of a blog post even if the victim knows enough to figure out what happened.