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twitter.com/EtTuCarl/statu It's 3 vulnerabilities in Skia, which is a 2D rendering library used by Android, Firefox and Chromium. It's widely used and the context where an attacker could gain code exec varies. For Chromium on Android it's in the Chrome or WebView renderer sandbox.

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Carl (fan parody)

@EtTuCarl

Feb 14, 2019

@DanielMicay Do you know exactly what part of Android does this (specific to built-in photo app, webview, or something else)? twitter.com/cybersecboardr…

Daniel Micay

@DanielMicay

Feb 14, 2019

There are other Android apps using it along applications on other platforms. There's a detailed post about the issues on the Project Zero blog: googleprojectzero.blogspot.com/2019/02/the-cu Can tell it has diverse apps using it from StackOverflow questions like stackoverflow.com/questions/4229 (C# on iOS).

stackoverflow.com

How to add rect using Skia Sharp and apply both fill color and stroke color to that object?

How to add rect or any shape using Skia Sharp and apply both fill color and stroke color to that object in iOS

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Skia sounds as awful as something I'd expect out of Google...

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They made it because Cairo has terrible performance and varying output across platforms. I'd expect that Cairo has bigger security problems too, but doesn't get nearly as much attention because it's not exposed in two of the major browsers as the 2D canvas implementation.

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Cairo was used exclusively by Firefox until 52. Performance is acceptable even on very old and embedded hardware. Dunno what you are talking about.

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Cairo performance for canvas and elsewhere was atrocious. It was a massive bottleneck and made rendering very CPU bound. Going from 5-10 fps to 60-120 fps for 2D games, etc. is a big deal. A large part of the issue is Cairo's API. Read Mozilla's posts. robert.ocallahan.org/2011/09/graphi

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Most users aren't running games in the browser but viewing websites. Switch away from Cairo was about competing with (and deprecating) Flash and about letting sites get orders of magnitude more resource-hungry (GPU-dependent), not about making performance acceptable.

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Performance was unacceptable simply for rendering and scrolling web pages consisting entirely of CSS, text and images without any JavaScript. There are also many applications based on Canvas including obvious cases like Google Maps but also lots of examples that are less obvious.

2:31 AM · Feb 16, 2019Twitter Web Client

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That's also after Mozilla put in lots of work to develop improvements and accelerated backends for Cairo. Firefox performance can still be sluggish on demanding web pages with complex HTML/CSS. Still often has lots of dropped frames / jank with popular sites on weaker hardware.

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And sure, most sites consume orders of magnitude more resources than they should need to deliver the same experience (with exceptions for web applications with real use cases for complex rendering). That's just the reality of the web, and people won't use Firefox if it's slow.

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Before these apps used canvas API, they were lightning fast on 2006 hardware. Canvas was a huge regression. The backend is a relatively minor issue; they're still 2 orders of magnitude slower than in 2006, even with skia.