CVE-2020-12270

React Native Bluetooth Scan in Bluezone 1.0.0 uses six-character alphanumeric IDs, which might make it easier for remote attackers to interfere with COVID-19 contact tracing by using many IDs. NOTE: the vendor disputes the relevance of this report because the recipient of an F1 alert will know it was a false alert if contact-history comparison fails (i.e., an F0 is not actually part of the contact history obtained from the device of this recipient, or this recipient is not actually part of the contact history obtained from the device of an F0)

Weakness

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected Software

Potential Mitigations

• Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.
• In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.
• Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a “random enough” number.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/112.html
• https://cwe.mitre.org/data/definitions/485.html
• https://cwe.mitre.org/data/definitions/59.html

References

• https://bluezone.ai/CVE
• https://github.com/BluezoneGlobal/bluezone-app/blob/afa15fcec391f0edc51d0486a4ca84dd2520bbb3/CHANGELOG.md
• https://github.com/BluezoneGlobal/bluezone-app/blob/afa15fcec391f0edc51d0486a4ca84dd2520bbb3/package.json#L27
• https://github.com/BluezoneGlobal/react-native-bluetooth-scan/blob/d9ee70fd594093a30e50b6e62a7593a8397c2dab/lib/android/src/main/AndroidManifest.xml#L11-L12
• https://github.com/BluezoneGlobal/react-native-bluetooth-scan/blob/d9ee70fd594093a30e50b6e62a7593a8397c2dab/lib/android/src/main/java/com/scan/BluezonerIdGenerator.java#L18-L28
• https://github.com/BluezoneGlobal/react-native-bluetooth-scan/blob/d9ee70fd594093a30e50b6e62a7593a8397c2dab/lib/android/src/main/java/com/scan/TraceCovidModule.java#L98
• https://vnhacker.blogspot.com/2020/04/vietnams-contact-tracing-app_26.html