CVE-2020-24722
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.
Does this matter?
Lower severity and a low EPSS score (2.46%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 2.46% probability · 84th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-294
- Affected
- exposure notifications project/exposure notifications
- Source
- cve@mitre.org
References
- http://packetstormsecurity.com/files/159496/GAEN-Protocol-Metadata-Deanonymization-Risk-Score-Inflation.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/Oct/12Exploit, Mailing List, Third Party Advisory
- https://blog.google/inside-google/company-announcements/update-exposure-notificationsThird Party Advisory
- https://github.com/google/exposure-notifications-internals/blob/main/en-risks-and-mitigations-faq.md#additional-considerationsThird Party Advisory
- http://packetstormsecurity.com/files/159496/GAEN-Protocol-Metadata-Deanonymization-Risk-Score-Inflation.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/Oct/12Exploit, Mailing List, Third Party Advisory
- https://blog.google/inside-google/company-announcements/update-exposure-notificationsThird Party Advisory
- https://github.com/google/exposure-notifications-internals/blob/main/en-risks-and-mitigations-faq.md#additional-considerationsThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.