VULNERABILITY INTELLIGENCE
CVE-2020-24722
CVSS score5.9 MEDIUM
EPSS probability2.46%
CISA KEVNot currently listed
Published2020-10-07
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
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.
Weakness classification
- nvd@nist.gov: CWE-294
Primary references
- cve@mitre.org — Exploit, Third Party Advisory, VDB Entry
- cve@mitre.org — Exploit, Mailing List, Third Party Advisory
- cve@mitre.org — Third Party Advisory
- cve@mitre.org — Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Exploit, Third Party Advisory, VDB Entry
- af854a3a-2127-422b-91ae-364da2661108 — Exploit, Mailing List, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory