AliExpress Fingerprinted Visitors With Inaudible Audio, Disrupting 1 Researcher’s Bluetooth Headphones
Updated
Updated · Ars Technica · Aug 24
AliExpress Fingerprinted Visitors With Inaudible Audio, Disrupting 1 Researcher’s Bluetooth Headphones
3 articles · Updated · Ars Technica · Aug 24
Summary
Matthew Callaghan traced a Bluetooth audio glitch to AliExpress after his phone audio cut out every time he opened the retailer’s homepage on his PC.
Two obfuscated scripts built a WebAudio graph that generated sawtooth waves and measured how each browser processed them, creating a device fingerprint.
Zero-volume gain kept the sounds inaudible to users, but the browser still processed the signal through the selected system audio path and sent the readings back to AliExpress.
The technique is an older form of browser fingerprinting and follows earlier reports that Brave already blocks AliExpress’s silent audio tracking.