CVE-2020-24722

** DISPUTED ** 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 v3.0 5.9 MEDIUM
CVSS v2.0 2.6 LOW

5.9^/10

CVSS v3.0 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

2.6^/10

CVSS v2.0 : LOW

Vector : AV:N/AC:H/Au:N/C:N/I:P/A:N

Exploitability : 4.9 / Impact : 2.9

Access Vector NETWORK

Access Complexity HIGH

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
http://seclists.org/fulldisclosure/2020/Oct/12	Exploit Mailing List Third Party Advisory
https://github.com/google/exposure-notifications-internals/blob/main/en-risks-and-mitigations-faq.md#additional-considerations	Third Party Advisory
https://blog.google/inside-google/company-announcements/update-exposure-notifications	Third Party Advisory
http://packetstormsecurity.com/files/159496/GAEN-Protocol-Metadata-Deanonymization-Risk-Score-Inflation.html	Exploit Third Party Advisory VDB Entry

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Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:exposure_notifications_project:exposure_notifications::::::android::*
	cpe:2.3:a:exposure_notifications_project:exposure_notifications::::::iphone_os::*

Information

Published : 2020-10-07 08:15

Updated : 2020-10-22 19:26

NVD link : CVE-2020-24722

Mitre link : CVE-2020-24722

JSON object : View

CWE

CWE-294

Authentication Bypass by Capture-replay

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Products Affected

exposure_notifications_project

exposure_notifications

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