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Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws

From The Wanderer <wanderer@fastmail.fm>
Newsgroups linux.debian.user
Subject Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws
Date 2018-01-04 18:40 +0100
Message-ID <v4hEK-dn-11@gated-at.bofh.it> (permalink)
References <v4hv3-a1-7@gated-at.bofh.it>
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On 2018-01-04 at 12:22, Curt wrote:

> https://arstechnica.com/gadgets/2018/01/meltdown-and-spectre-every-modern-processor-has-unfixable-security-fladdws/U
> 
> 
> TL;DR
> 
> Windows, Linux, and macOS have all received security patches that 
> significantly alter how the operating systems handle virtual memory
> in order to protect against a hitherto undisclosed flaw.
> ...
> In the immediate term, it looks like most systems will shortly have 
> patches for Meltdown. At least for Linux and Windows, these patches 
> allow end-users to opt out if they would prefer. The most vulnerable 
> users are probably cloud service providers; Meltdown and Spectre can 
> both in principle be used to further attacks against hypervisors, 
> making it easier for malicious users to break out of their virtual 
> machines.
> ...
> For typical desktop users, the risk is arguably less significant.
> While both Meltdown and Spectre can have value in expanding the scope
> of an existing flaw, neither one is sufficient on its own to, for
> example, break out of a Web browser.
> 
> Apparent moral of story for CPU: don't speculate (but it's
> significantly *slower*).

https://spectreattack.com/ has the best and most concise summary I've
seen yet, as well as links to various other places for in-depth details
(whitepapers and blog posts).


The situation as I understand it is basically that:

* Meltdown affects all Intel CPUs released since about 1995, except for
Itanium models and pre-2013 Atom models.

* Spectre appears to affect Intel, AMD, and ARM chips alike, going back
who-knows-how-far.

* Meltdown can be mitigated by security patches which people are rushing
out, but doing so has a performance cost, anywhere from 5% to 30%
depending on various factors.

* Spectre can only be fixed (or even meaningfully mitigated)
per-program, and doing so isn't necessarily trivial.

* Meltdown is relatively easy and straightforward to trigger, once you
know how.

* Spectre is harder to trigger and/or exploit, but still possible.

* Nobody knows whether either of these is being exploited in the wild.


Also,
https://techreport.com/news/33026/researchers-reveal-meltdown-and-spectre-cpu-exploits?post=1064251
is what looks to me like an "as near to layman's terms as we're likely
to get" explanation of how the Spectre exploit actually works.

-- 
   The Wanderer

The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore all
progress depends on the unreasonable man.         -- George Bernard Shaw

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Thread

“Meltdown” and  “Spectre”: Every modern processor has  unfixable security flaws Curt <curty@free.fr> - 2018-01-04 18:30 +0100
  Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws The Wanderer <wanderer@fastmail.fm> - 2018-01-04 18:40 +0100
  Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws Michael Fothergill <michael.fothergill@gmail.com> - 2018-01-04 18:50 +0100
    Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws The Wanderer <wanderer@fastmail.fm> - 2018-01-04 19:00 +0100
      Re: “Meltdown” and  “Spectre”: Every modern processor has  unfixable security flaws Tixy <tixy@yxit.co.uk> - 2018-01-04 19:20 +0100
        Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws The Wanderer <wanderer@fastmail.fm> - 2018-01-04 19:30 +0100
      Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws Michael Fothergill <michael.fothergill@gmail.com> - 2018-01-04 19:40 +0100
        Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws Nicholas Geovanis <nickgeovanis@gmail.com> - 2018-01-04 20:00 +0100
      Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws Jack Dangler <tdldev@gmail.com> - 2018-01-05 13:50 +0100
        Re: “Meltdown” and “Spectre”: Every modern processor has  unfixable security flaws <tomas@tuxteam.de> - 2018-01-05 14:00 +0100
          Re: "Meltdown" and "Spectre": Every modern processor has unfixable security flaws "Thomas Schmitt" <scdbackup@gmx.net> - 2018-01-05 14:50 +0100
            Re: "Meltdown" and "Spectre": Every modern processor has unfixable  security flaws <tomas@tuxteam.de> - 2018-01-05 15:40 +0100
              Re: "Meltdown" and "Spectre": Every modern processor has unfixable security flaws "Thomas Schmitt" <scdbackup@gmx.net> - 2018-01-05 16:50 +0100
                Re: "Meltdown" and "Spectre": Every modern processor has unfixable  security flaws <tomas@tuxteam.de> - 2018-01-05 17:10 +0100
                [OFFTOPIC] Re: "Meltdown" and "Spectre": Every modern processor has unfixable security flaws Stefan Monnier <monnier@iro.umontreal.ca> - 2018-01-05 19:10 +0100
                Re: [OFFTOPIC] Re: "Meltdown" and "Spectre": Every modern processor  has unfixable security flaws SDA <marathon.durandal@gmail.com> - 2018-01-08 02:40 +0100
                Re: [OFFTOPIC] Re: "Meltdown" and "Spectre": Every modern processor  has unfixable security flaws Curt <curty@free.fr> - 2018-01-08 11:30 +0100
                Re: [OFFTOPIC] Re: "Meltdown" and "Spectre": Every modern processor  has unfixable security flaws Tom Furie <tom@furie.org.uk> - 2018-01-08 13:10 +0100
          Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws Nicholas Geovanis <nickgeovanis@gmail.com> - 2018-01-05 17:40 +0100
            Re: “Meltdown” and “Spectre”: Every modern processor has  unfixable security flaws <tomas@tuxteam.de> - 2018-01-05 17:50 +0100
            [OFFTOPIC] Re: “Meltdown” and  “Spectre”: Every modern processor has unfixable  security flaws Stefan Monnier <monnier@iro.umontreal.ca> - 2018-01-05 19:10 +0100
  Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws francis picabia <fpicabia@gmail.com> - 2018-01-04 19:10 +0100
    Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws bw <bwtnguy@yahoo.com> - 2018-01-04 19:20 +0100
    Re: “Meltdown” and “Spectre”: Every modern processor has unfixable security flaws The Wanderer <wanderer@fastmail.fm> - 2018-01-04 19:20 +0100

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