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I think the comparison between CPU and software exploits holds at a very high level, but in the case of software the gap between internal and external researche

I think the comparison between CPU and software exploits holds at a very high level, but in the case of software the gap between internal and external researches seems lower. Much software is open-source, in which case the play field is almost level and even closed source software is available in assembly which exposes the entire attack surface in a reasonably consumable form. Software reverse-engineering is a hugely popular, fairly accessible field with good tools. Hardware not so much. > When billions use something I expect them to find more problems, flaws, and exploits in it than the creator/manufacturer did. The presence of this does nothing to indicate (or refute) any further conclusion about why. To be very clear none of these errors have been found by billions of random users but by a few interested third parties: many of them working as students with microscopic funding levels and no apparent inside information. I'm not actually suggesting that the nefarious explanation holds: I'm genuinely curious.

zamadatix 3y ago
I'm not sure I agree significant gaps in the playing fields are really there. By significant I mean something that explains it should be e.g. 10x harder or something to the point it's supposed to be suspicious how the ratio is indicative of something off. Sure, you don't get to see how they laid out the transistors of the CPU but that's not how these attacks work it's by some oversight in memory handling not that different from software. They analyze how individual assembly instructions behave in certain scenarios vs how they are designed to behave. Compare this to the process of attacking closed source software like Windows, sift through a bunch of assembly in a debugger and see what gets left behind or compared incorrectly, and it's not glaringly different just because hardware is involved. Difficult, sure, but far from anything to suggest it should be uncommon. More importantly, by definition you don't really get to see all of the things they do catch. Maybe they are getting 90% of other related vulnerabilities with the patches but you only hear about the 10% that weren't covered by it because that's the only thing someone is going to publish/get a cve for/make the front page of HN. The point isn't that billions of users all actively try to exploit software it's that if you have billions of users then even if 0.01% try to then that's still a hell of a lot more external bug finders than internal bug finders. Yeah nothing against you or genuine curiosity it's just when a comment sets up a series of logic and concludes with a leading question then the conversation is damned to largely revolve around the leading question instead of genuine answers.
- BeeOnRope 3y ago
  I dabble in this space (hardware reverse-engineering) and write software for a living and in my opinion the gaps are huge. I should disclose have been paid by a chip-maker for a blog post that I wrote which "disclosed" an optimization which could be uses for a side channel attack (though I did not even suggest that aspect) and which was subsequently patched away via a microcode update. The whole process was very surprising to me in that there must have been several people inside the chip-maker who knew about the optimization I described in much deeper detail ... after all they conceived and implemented it. So by what path does a blog post mentioning it get treated as the disclosure that results it it being removed when they knew about it all along? > that's not how these attacks work it's by some oversight in memory handling not that different from software. I think it is very different. Assembly is merely a somewhat less convenient form of the original semantics that embeds all the relevant semantics related to the attack surface since the original source has been "erased". Many analysis tools such as fuzzers operate directly on assembly with little loss in functionality. These attacks are against completely unspecified aspects of the instruction execution and lean heavily on the actual hardware implementation (almost at the level of "how the transistors are laid out") such as what hidden buffers are used, when they are filled, how they are shared with sibling threads, etc. In my experience there are very few people interested in these details outside of the vendors themselves and these folks and the ones creating the exploits would fit in a modestly sized lecture hall. The scope has increased a bit lately (see Tavis's fuzzer work) but it was originally a small group with little or no funding.
  - zamadatix 3y ago
    Do you have a link for the blog post? I'd love to read more about that. Since we disagree in how big the gap is, and neither of us is going to get a satisfactory answer out of a chip maker any time soon, perhaps a different argument: there are plenty or microcode updates all the time, doing more than fix just security bugs. There are also security bugs like M1racles which have nothing to do with performance incentives. If these can all be explained by a lecture halls worth of people finding things most wouldn't post release of the chip then why does the same situation on security issues require unique explanation?

zamadatix 3y ago

I'm not sure I agree significant gaps in the playing fields are really there. By significant I mean something that explains it should be e.g. 10x harder or something to the point it's supposed to be suspicious how the ratio is indicative of something off. Sure, you don't get to see how they laid out the transistors of the CPU but that's not how these attacks work it's by some oversight in memory handling not that different from software. They analyze how individual assembly instructions behave in certain scenarios vs how they are designed to behave. Compare this to the process of attacking closed source software like Windows, sift through a bunch of assembly in a debugger and see what gets left behind or compared incorrectly, and it's not glaringly different just because hardware is involved. Difficult, sure, but far from anything to suggest it should be uncommon. More importantly, by definition you don't really get to see all of the things they do catch. Maybe they are getting 90% of other related vulnerabilities with the patches but you only hear about the 10% that weren't covered by it because that's the only thing someone is going to publish/get a cve for/make the front page of HN. The point isn't that billions of users all actively try to exploit software it's that if you have billions of users then even if 0.01% try to then that's still a hell of a lot more external bug finders than internal bug finders. Yeah nothing against you or genuine curiosity it's just when a comment sets up a series of logic and concludes with a leading question then the conversation is damned to largely revolve around the leading question instead of genuine answers.

BeeOnRope 3y ago
I dabble in this space (hardware reverse-engineering) and write software for a living and in my opinion the gaps are huge. I should disclose have been paid by a chip-maker for a blog post that I wrote which "disclosed" an optimization which could be uses for a side channel attack (though I did not even suggest that aspect) and which was subsequently patched away via a microcode update. The whole process was very surprising to me in that there must have been several people inside the chip-maker who knew about the optimization I described in much deeper detail ... after all they conceived and implemented it. So by what path does a blog post mentioning it get treated as the disclosure that results it it being removed when they knew about it all along? > that's not how these attacks work it's by some oversight in memory handling not that different from software. I think it is very different. Assembly is merely a somewhat less convenient form of the original semantics that embeds all the relevant semantics related to the attack surface since the original source has been "erased". Many analysis tools such as fuzzers operate directly on assembly with little loss in functionality. These attacks are against completely unspecified aspects of the instruction execution and lean heavily on the actual hardware implementation (almost at the level of "how the transistors are laid out") such as what hidden buffers are used, when they are filled, how they are shared with sibling threads, etc. In my experience there are very few people interested in these details outside of the vendors themselves and these folks and the ones creating the exploits would fit in a modestly sized lecture hall. The scope has increased a bit lately (see Tavis's fuzzer work) but it was originally a small group with little or no funding.
- zamadatix 3y ago
  Do you have a link for the blog post? I'd love to read more about that. Since we disagree in how big the gap is, and neither of us is going to get a satisfactory answer out of a chip maker any time soon, perhaps a different argument: there are plenty or microcode updates all the time, doing more than fix just security bugs. There are also security bugs like M1racles which have nothing to do with performance incentives. If these can all be explained by a lecture halls worth of people finding things most wouldn't post release of the chip then why does the same situation on security issues require unique explanation?