Security Advisory
CVE-2020-24722
CVE vulnerability detail — eXtreme Datacenter Security Operations
Description
An issue was discovered in the GAEN (aka Google/Apple Exposure Notifications) protocol through 2020-10-05, as used in COVID-19 applications on Android and iOS. The encrypted metadata block with a TX value lacks a checksum, allowing bitflipping to amplify a contamination attack. This can cause metadata deanonymization and risk-score inflation. NOTE: the vendors position is "We do not believe that TX power authentication would be a useful defense against relay attacks.