I Know Where You've Been: Geo-Inference Attacks via the Browser Cache

To provide more relevant content and better responsiveness, many websites customize their services according to users' geolocations. However, if geo-oriented websites leave location-sensitive content in the browser cache, other sites can sniff that content via side channels. The authors' case studies demonstrate the reliability and power of geo-inference attacks, which can measure the timing of browser cache queries and track a victim's country, city, and neighborhood. Existing defenses cannot effectively prevent such attacks, and additional support is required for a better defense deployment.