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Microsoft’s Secure Boot has been broken for a decade and no one noticed until now (www.welivesecurity.com)
submitted 3 months ago by to c/technology@lemmy.world
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[–] 1 point 3 months ago (2 children)

Yes.

Is UEFI shim = secure boot?

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  • [–] 4 points 3 months ago* (1 child)

    No.

    Secure Boot is basically a 'lock', on the UEFI.

    UEFI - Shim is basically a 'lockpick'.

    UEFI is the first step in your computer booting, turning on.

    So, if Secure Boot is supposed to be a 'lock', that limits who can access the UEFI ... but it turns out that there are many, old, UEFI - Shims, that defeat that 'lock'... then Secure Boot is not a good 'lock'.

    I don't mean to be rude but it seems like there might be a bit of language confusion going on here... In English, a 'shim' is a kind of crude/simple tool that can be used to break or bypass some actual physical locks.

    So 'UEFI-Shim' basically means 'a thing that breaks into your UEFI'.

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  • [–] 3 points 3 months ago*

    I don't think there's a language barrier here. I'm fluent in English, and I know what a shim is, both IRL and in the software world. I've just not run into it in a boot loader context before. And I'm not really knowledgeable when it comes to secure boot, either. Just trying to understand. 🙂

    Are you sure that's a good phrasing though, "that breaks into your UEFI"?

    A shim is usually something that you use to add or modify functionality by interception, right? Like a middle-ware, almost. So these old shims, are they responsible for functionality that directly has to do with Secure Boot, or something else?

    If so, they are broken — i.e. not fulfilling their purpose.

    If something else, they are not broken. They are just breaking something else, or making it vulnerable.

    Am I making sense? Does it not make sense? Because after all, I don't know much about the details of the subject matter. 😁

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