AliExpress runs silent WebAudio fingerprinting that breaks Bluetooth multipoint
AliExpress's homepage silently runs two WebAudio fingerprinting scripts that kept a user's multipoint Bluetooth headphones from switching audio to their phone. The scripts, collina.js and fireyejs.js, create zero-gain audio graphs connected to the system destination, which browsers process even when muted. Blocking them with uBlock Origin restored normal headphone behavior.
Perhaps if AliExpress wasn't blocking my music I never would've looked into what the site was doing.
- lxgr
I wish such shenanigans would simply trigger the little speaker icon most browser display on tabs these days.
Given that they don't (at least in my experience), I'm assuming "playing silent audio" is a sufficiently common thing for websites to do to have motivated browsers into doing the slightly more complicated thing of actually analyzing audio streams for content...
Now I wonder, does this also allow websites to continue running in the background on mobile browsers? Playing media is one of the very few things that can convince iOS Safari to keep a tab running indefinitely, in my experience.
- mgerdts
With my previous hearing aid I noticed that visiting a wide variety of web sites would cause a change in the amplification of environmental noise. I always assumed it was doing something with Bluetooth, and probably not for a good reason. This is with an iPhone 13 and one Kirkland/phonak hearing aid.
I haven’t noticed this recently, but I also now have two newer Phonak hearing aids and a few iOS updates have happened. Maybe the silent Bluetooth shenanigans are less disruptive to my new aids or the programming is different. Surely shenanigans continue.
- patspam
I noticed in the last few weeks that if I’d recently opened the AliExpress iOS app (ie. it was backgrounded) my car audio would freak out thinking I was giving it an audio command. Killing the AliExpress app immediately fixed the problem. After seeing it happen more than once I assumed it was something dodgey and uninstalled the app.
- fuzzy2
When I visit an article on a popular German tech news website, it interrupts music playback on my iPad (the website takes audio focus). I bet they do something similar.
- rootsudo
I’ve noticed this and on other apps too, it breaks AirPods and when background playing Spotify it’s very obvious.
Thanks for investigating! Makes sense it’s also in the taobao app on ios too.
- forestry
So Apple will remove them from the App Store. Thats their whole argument for their closed system - they’ll protect users from malicious apps. Right?
- compsciphd
i'd argue that perhaps the ability to play audio should be permission gated, much like the ability to use webcam/microphone.
However, I'd bet that many people will gladly allow aliexpress to play audio as there are probably videos on the site that people want to play and listen to.
With that said, its possible that this can be only a use once permission. Even if I want to shop at aliexpress if I know they are doing this, I'll be more willing to be bothered every time I want to play a video with audio to approve it if this bothers me.
- miki123211
Ah, so that's what Wolt (Doordash but in Europe) is doing.
I noticed that Voice Over (iOS screen reader) crackles and randomly changes volume when using the app, but I attributed it to standard iOS weirdness, and possibly misuse of some iOS API. Now I'm thinking that this may very well be fingerprinting.