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Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

arstechnica.com

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Re: Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

#61

Post by josefx »

vacuity wrote: post #41
stuaxo wrote: post #23

Has anyone made a law about this sort of thing yet? If not I'll have it: Axons Law - Any sufficiently fast optimisation will be repurposed as an attack vector.

Time to write a comprehensive paper titled "Optimizations Considered Harmful". Seriously though, it's distressing how we have Spectre and Meltdown and whatnot. We've gone too far trying to squeeze every drop of performance out of hardware (Electron is for balance, of course /s) and now we pay the price.

> Time to write a comprehensive paper titled "Optimizations Considered Harmful".

Apparently the other browsers went with "don't inject untrusted third party code into a site".

Re: Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

#62

Post by j16sdiz »

andyferris wrote: post #44
mmastrac wrote: post #5

Earlier quoted context omitted.

I know it's a non-serious play on the piracy/theft meme, but in seriousness, "stealing" is probably not the right word for private information leakage.

I think a sentences like "the Russian spy stole American military secrets", "a hacker stole my password" and "a very slow cross-site SVG filter attack stole a copy of my pixels" are perfectly valid and clear English. Piracy is the odd-one-out because it's about "stealing" non-secret information, which seems non-sensical.

"Stealing" non-secret information is like "stealing" toilet paper from public toilets.

Re: Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

#63

Post by Asraelite »

twelvechairs wrote: post #29
vessenes wrote: post #25

This is a solid attack. I wouldn't call it beautiful, it's more like a well-considered thorough engineering tour-de-force. I'm horrified but applaud the team. Here's how it works: a stack of SVG filters is created. These filters are constructed so that they will tend to be faster processing a dark pixel than they will be processing a light pixel. An iframe is loaded up by the attacking site, pointing at, say, a banki…

Why isn't the proposed fix "don't allow cross-site iframe injection"? It is surely a security risk that other browsers have taken that stand on no?

Site permissions are already a thing for e.g. video and location access. I don't see why they're not extended to all these other attack vectors: WebGPU, WebRTC, canvas, Web Audio, iframes, precise timing functions, WASM etc.

Most sites don't need any of these features so why not make them opt-in and per-site?

Re: Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

#64

Post by nicce »

Asraelite wrote: post #63
twelvechairs wrote: post #29

Earlier quoted context omitted.

Why isn't the proposed fix "don't allow cross-site iframe injection"? It is surely a security risk that other browsers have taken that stand on no?

Site permissions are already a thing for e.g. video and location access. I don't see why they're not extended to all these other attack vectors: WebGPU, WebRTC, canvas, Web Audio, iframes, precise timing functions, WASM etc. Most sites don't need any of these features so why not make them opt-in and per-site?

95% of the people have no idea what they mean and just click yes.

Re: Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

#68

Post by quickthrower2 »

baz00 wrote: post #58
AlexCoventry wrote: post #24

Earlier quoted context omitted.

What is it with these strangers who want to run stuff on my computer without my explicit permission?? :-)

Exactly! If I want to run something on my computer I’ll damn well download a tar file and spend several hours arguing with autoconf! :)

Define run

Re: Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

#69

Post by PawgerZ »

codetrotter wrote: post #19
kube-system wrote: post #9

Earlier quoted context omitted.

The word is used to refer to taking something without the right to do so. The key part is the lack of a right to do so, not depriving the owner. e.g. If you take someone's car while they're away on vacation and bring it back before they get home, it is still stealing, even if you topped up the tank and they never noticed.

Analogies never work. The reason that it is wrong to take my car, even if I don’t notice, are multiple: - You are still depriving me of the possibility of using my own car, even if it happened to be the case that I didn’t need it. I could have come home early. I could have told some friend or family to pick up my car so that they could use it. I could have had an appointment that someone would come by to service my c…

> It still causes wear and tear on my car if you use it. - It still causes wear and tear on hardware if you use it

> You could get into an accident, which could hurt you and damage my car. - You could have a data breach, which could hurt you and damage my privacy

> I don’t want random strangers to sit their butts in my car. - I don't want random strangers to put their eyes on my private browsing

> etc - etc

Re: Sidechannel pixel-stealing attack works in Chromium on all modern GPUs

#70

Post by treyd »

stuaxo wrote: post #23

Has anyone made a law about this sort of thing yet? If not I'll have it: Axons Law - Any sufficiently fast optimisation will be repurposed as an attack vector.

The problem really seems to be with running arbitrary untrusted code.
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