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Comment by ddworken | Hacker News Reader

Last year Chrome published a great paper on this[1]. The summary is that we no longer think it is possible to completely prevent speculative execution bugs. A big focus nowadays is on providing tools (mainly via HTTP headers) that allow a website to opt-in to a more strict security model where specific sensitive resources can't end up in a process that is running untrusted code. If you're curious, check out this[2] document which explains a bunch of these different mechanisms.

Disclosure: I work at Google and am involved in deploying some of these features internally.

[1]: https://arxiv.org/pdf/1902.05178.pdf [2]: https://w3c.github.io/webappsec-post-spectre-webdev/

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> Chromium’s threat model, for instance, now asserts that "active web content … will be able to read any and all data in the address space of the process that hosts it"

This was a huge WTF to me. I have been doing web dev for 10+ years and can barely get origin based security right. Now we're expected to understand process level security boundaries too???

That said, are there any resources explaining how the chromium process works? It has always been a black box to me. For example if a form is being autofilled, don't those personal info/passwords have to be loaded into memory? There's an infinite amount of things that I thought was inaccessible solely because there's no JS api to access the data that I now need to think about. Direct memory access is just a huge can of worms, no?

Yeah, I think it is a bit unfortunate that there doesn't seem to be any way of hiding this implementation detail from developers. In general though, Chrome is very thoughtfully designed so things mostly work as you'd hope. The core of the process model is that each site (e.g. `ycombinator.com` not `news.ycombinator.com`) gets its own process. This [0] has a great list of things they've considered when designing site-isolation. For example, Chrome's password manager does respect site isolation and is designed to operate across multiple processes[1].

[0]: https://chromium.googlesource.com/chromium/src/+/master/docs... [1]: https://chromium.googlesource.com/chromium/src/+/master/comp...

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