5.9
CVSSv3

CVE-2020-24722

Published: 07/10/2020 Updated: 17/05/2024
CVSS v2 Base Score: 2.6 | Impact Score: 2.9 | Exploitability Score: 4.9
CVSS v3 Base Score: 5.9 | Impact Score: 3.6 | Exploitability Score: 2.2
VMScore: 231
Vector: AV:N/AC:H/Au:N/C:N/I:P/A:N

Vulnerability Summary

An issue exists 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.

Vulnerability Trend

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Mailing Lists

GAEN Protocol Metadata Deanonymization and Risk-score Inflation Issues (CVE-2020-24722) Summary The TX Power value in the metadata in the beacon of the GAEN protocol used by the corona/contact tracing app allows for attackers to influence risk-score calculations in their favor, the same metadata can also be used to deanonymize diagnosed users bas ...