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I think there is another important reason to extend embargoes aside preparing patches. Vulnerabilities like Meltdown and Spectre are in fact a whole new family

I think there is another important reason to extend embargoes aside preparing patches. Vulnerabilities like Meltdown and Spectre are in fact a whole new family of attack methods. It would take time to fully evaluate the extent of the problem. I would not be surprised that we learn new variants of Spectre in the coming future.

emn13 9y ago
These classes of attacks are not new. Timing attack in crypto have been widely used for a long time. And even specifically in CPU's there was stuff like http://www.daemonology.net/papers/htt.pdf http://www.daemonology.net/papers/htt.pdf and http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.190.1003&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.190... over ten years ago(!). To quote that last paper: > We show how processor architecture features such as simultaneous multithreading, control speculation and shared caches can inadvertently accelerate such covert channels or enable new covert channels and side channels. We first illustrate the reality and severity of this problem by describing concrete attacks. So not just were side-channel attacks on CPUs documented; specifically the dangers of speculative execution and caching on intel cpus (there: the Itanium) was documented. It's inconceivable that this comes as a surprise to Intel. They're playing the public for fools. Of course some of this is intrinsic: speculative loading, caching, and accurate timers are an intrinsic problem: an JIT running in the same process as the JITted code will not be able to keep secrets from that JITted code while all three are in play. But intel specifically also allowed this across memory protection boundaries, which isn't necessary.
- xucheng 9y ago
  Yes, I am aware of them and agree with you. In fact, cache-miss side channel attacks are known by academics for years as well. However, this is the first time someone combining various of previous techniques (timing, cache-miss, speculative loading etc.) together to make this attack work. Quote from the meltdown paper: > We expect that Meltdown and Spectre open a new field of research to investigate in what extent performance optimizations change the microarchitectural state, how this state can be translated into an architectural state, and how such attacks can be prevented. So we won't see the last of Spectre.
  - emn13 9y ago
    Right, so to stick a label on it: the exploit is novel, the vulnerability is not. Why does that matter? Because people seem to imply intel isn't to blame here; that since the attacks were unforeseen, it's essentially just bad luck. But that's not the case: the risky bits of architecture were known. It's like finding a memory corruption vulnerability and then deciding not to fix it since you don't also know of an exploit - that's just being careless. Furthermore; finding holes like this isn't some divine act; although there is luck and skill involved there's no question that others can do so too. Even if an attack were completely new, you have to ask yourself how hard it was to find. Does a supplier have any responsibility to provide secure things? Then they should be looking for these kinds of holes. Obviously to a novice any hack like this looks almost magical - but there's a risk that by interpreting any novel attack as not-their-fault that the vulnerable supplier never bothers trying to make anything secure. Intel was being careless. They should definitely have known this was exploitable even without knowing how to exploit it. And it's at least conceivable that they could have found this or an exploit like this if they had tried.
  - guitarbill 9y ago
    > We expect that Meltdown and Spectre open a new field of research to investigate in what extent performance optimizations change the microarchitectural state, how this state can be translated into an architectural state, and how such attacks can be prevented. Not to be cynical or downplay the research, but that's the kind of thing you (have to?) put into papers to make getting research funding easier in future. Hardly a new field, just very difficult to do research on.

emn13 9y ago

These classes of attacks are not new. Timing attack in crypto have been widely used for a long time. And even specifically in CPU's there was stuff like http://www.daemonology.net/papers/htt.pdf http://www.daemonology.net/papers/htt.pdf and http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.190.1003&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.190... over ten years ago(!). To quote that last paper: > We show how processor architecture features such as simultaneous multithreading, control speculation and shared caches can inadvertently accelerate such covert channels or enable new covert channels and side channels. We first illustrate the reality and severity of this problem by describing concrete attacks. So not just were side-channel attacks on CPUs documented; specifically the dangers of speculative execution and caching on intel cpus (there: the Itanium) was documented. It's inconceivable that this comes as a surprise to Intel. They're playing the public for fools. Of course some of this is intrinsic: speculative loading, caching, and accurate timers are an intrinsic problem: an JIT running in the same process as the JITted code will not be able to keep secrets from that JITted code while all three are in play. But intel specifically also allowed this across memory protection boundaries, which isn't necessary.

xucheng 9y ago
Yes, I am aware of them and agree with you. In fact, cache-miss side channel attacks are known by academics for years as well. However, this is the first time someone combining various of previous techniques (timing, cache-miss, speculative loading etc.) together to make this attack work. Quote from the meltdown paper: > We expect that Meltdown and Spectre open a new field of research to investigate in what extent performance optimizations change the microarchitectural state, how this state can be translated into an architectural state, and how such attacks can be prevented. So we won't see the last of Spectre.
- emn13 9y ago
  Right, so to stick a label on it: the exploit is novel, the vulnerability is not. Why does that matter? Because people seem to imply intel isn't to blame here; that since the attacks were unforeseen, it's essentially just bad luck. But that's not the case: the risky bits of architecture were known. It's like finding a memory corruption vulnerability and then deciding not to fix it since you don't also know of an exploit - that's just being careless. Furthermore; finding holes like this isn't some divine act; although there is luck and skill involved there's no question that others can do so too. Even if an attack were completely new, you have to ask yourself how hard it was to find. Does a supplier have any responsibility to provide secure things? Then they should be looking for these kinds of holes. Obviously to a novice any hack like this looks almost magical - but there's a risk that by interpreting any novel attack as not-their-fault that the vulnerable supplier never bothers trying to make anything secure. Intel was being careless. They should definitely have known this was exploitable even without knowing how to exploit it. And it's at least conceivable that they could have found this or an exploit like this if they had tried.
- guitarbill 9y ago
  > We expect that Meltdown and Spectre open a new field of research to investigate in what extent performance optimizations change the microarchitectural state, how this state can be translated into an architectural state, and how such attacks can be prevented. Not to be cynical or downplay the research, but that's the kind of thing you (have to?) put into papers to make getting research funding easier in future. Hardly a new field, just very difficult to do research on.