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    FFmpeg dealing with a security researcher

    (twitter.com)
    104 points trollied | 17 comments | 01 Nov 25 20:59 UTC | HN request time: 0.001s | source | bottom
    1. TheChaplain ◴[01 Nov 25 21:42 UTC] No.45785676[source]▶
    The comments from the public.. Just wow we are doomed..

    To explain, Googles vulnerability scanner found a problem in an obscure decoder for a 1990s game files (Lucasfilm Smush). Devs are not happy they get timewasting reports on stuff that rarely anyone ever uses except an exceptionally tiny group.

    Then people start berating them without even knowing the full story...

    replies(3): >>45785704 #>>45785787 #>>45786348 #
    2. cebert ◴[01 Nov 25 21:47 UTC] No.45785704[source]▶
    I could see a compromise where if there are obscure codecs that may not be as secure, FFmpeg would present a warning before loading the file. This way, the user would have the option to decide whether to load the file or not. By default, potentially malicious files would not be loaded, which could prevent them from being used as part of an exploit. This seems like a reasonable compromise.
    replies(1): >>45785749 #
    3. kvemkon ◴[01 Nov 25 21:53 UTC] No.45785749[source]▶
    > FFmpeg would present a warning

    Reminds me of gstreamer plugins being separated in "base", "good", "bad" and "ugly" sets.

    4. lukeschlather ◴[01 Nov 25 21:57 UTC] No.45785787[source]▶
    Google operates a transcoder API which I suspect is just ffmpeg under the hood, and if you assume that they accept any input file, they really can't afford for decoders to have security vulnerabilities. Of course, then Google should be coming with more resources and not just filing bugs because it's Google that has the unusual use case.
    replies(3): >>45785977 #>>45786069 #>>45786153 #
    5. vreg ◴[01 Nov 25 22:24 UTC] No.45785977[source]▶
    If that is true then Google should be strictly sandboxing ffmpeg and filtering the input before it even gets there. A solid defense-in-depth approach would make sure it's highly unlikely this vulnerable code would be reached, and if it was, there would be effectively no impact.

    They should be building ffmpeg with a minimal feature set anyway, so none of these obscure codecs end up included in the final binary.

    6. tkfoss ◴[01 Nov 25 22:38 UTC] No.45786069[source]▶
    Those decoders aren't even compiled and activated in the released binaries. But in any case, why would that be FFMPEGs problem?
    replies(1): >>45788090 #
    7. chris_wot ◴[01 Nov 25 22:47 UTC] No.45786153[source]▶
    Then they can certainly afford to supply patches.
    8. haskellshill ◴[01 Nov 25 23:11 UTC] No.45786348[source]▶
    >rarely anyone ever uses

    It's enabled by default so all that's required to exploit it would be to construct a payload file and name it movie.mp4

    replies(1): >>45786470 #
    9. defrost ◴[01 Nov 25 23:31 UTC] No.45786470[source]▶
    If only Google had the ability to custom compile FFmpeg to only include robust mainstream codecs.

    In such a would they might even handball submitted obscure codecs to a full build in a sandbox to track bleeding edge malware.

    replies(2): >>45786561 #>>45789812 #
    10. Ukv ◴[01 Nov 25 23:45 UTC] No.45786561{3}[source]▶
    To my understanding this bug would affect anyone using ffmpeg on untrusted input. Google may already be limiting to certain codecs in their own use, but should still report the issue (as they have here).
    replies(1): >>45787710 #
    11. GaryBluto ◴[02 Nov 25 03:41 UTC] No.45787710{4}[source]▶
    Yeah but who cares about them, right? It's a volunteer project don't you know.
    12. yegle ◴[02 Nov 25 05:48 UTC] No.45788090{3}[source]▶
    Please stop spreading this misinformation. At least in Debian this is enabled by default (and as another post indicates, Ubuntu as well).

    Run the following command to confirm:

    ffmpeg -codecs|grep sanm

    replies(1): >>45795901 #
    13. haskellshill ◴[02 Nov 25 12:25 UTC] No.45789812{3}[source]▶
    Right, they probably already mitigated this bug in their own usage. Which is exactly why reporting the bug is a FAVOR to ffmpeg. Would you rather they just quietly fix it on their own and not report it to the maintainers?
    replies(2): >>45789870 #>>45792499 #
    14. defrost ◴[02 Nov 25 12:36 UTC] No.45789870{4}[source]▶
    > Right, they probably already mitigated this bug in their own usage.

    Indeed. A step so obvious it renders comments such as this:

      It's enabled by default so all that's required to exploit it would be to construct a payload file and name it movie.mp4
    moot.

    > Which is exactly why reporting the bug is a FAVOR to ffmpeg.

    Not sure you have to SHOUT the obvious.

    > Would you rather they just quietly fix it on their own and not report it to the maintainers?

    What do you suppose the answer to that question to be?

    replies(1): >>45796087 #
    15. array_key_first ◴[02 Nov 25 18:54 UTC] No.45792499{4}[source]▶
    I would rather they fix it and submit a patch like normal fucking people.
    16. astrange ◴[03 Nov 25 04:31 UTC] No.45795901{4}[source]▶
    If you're using ffmpeg it's recommended to just enable the things you need, or only accept some container formats. But yes, in a generic package everything is enabled.
    17. Rebelgecko ◴[03 Nov 25 05:22 UTC] No.45796087{5}[source]▶
    There's this weird "damned if you do, damned if you don't" situation on social media where people try to help and get reamed for not doing enough. Taylor Swift donated $500k to charity and people complaining she didn't round up to a million. After all, she can afford it.

    But she ends up getting more criticism than the billionaire who donates nothing. Seems unfair but I guess it's human nature.