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 vendor's position is "We do not believe that TX power authentication would be a useful defense against relay attacks.
Scores
CVSS v3
5.9
EPSS
0.0032
EPSS Percentile
54.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Details
CWE
CWE-294
Status
published
Products (1)
exposure_notifications_project/exposure_notifications
< 2020-10-05 (2 CPE variants)
Published
Oct 07, 2020
Tracked Since
Feb 18, 2026