CVE-2023-38291

An issue was discovered in a third-party component related to ro.boot.wifimacaddr, shipped on devices from multiple device manufacturers. Various software builds for the following TCL devices (30Z and 10L) and Motorola devices (Moto G Pure and Moto G Power) leak the Wi-Fi MAC address to a system property that can be accessed by any local app on the device without any permissions or special privileges. Google restricted third-party apps from directly obtaining non-resettable device identifiers in Android 10 and higher, but in these instances they are leaked by a high-privilege process and can be obtained indirectly. The software build fingerprints for each confirmed vulnerable device are as follows: TCL A3X (TCL/A600DL/Delhi_TF:11/RKQ1.201202.002/vAAZ:user/release-keys, TCL/A600DL/Delhi_TF:11/RKQ1.201202.002/vAB3:user/release-keys, TCL/A600DL/Delhi_TF:11/RKQ1.201202.002/vAB7:user/release-keys, TCL/A600DL/Delhi_TF:11/RKQ1.201202.002/vABA:user/release-keys, TCL/A600DL/Delhi_TF:11/RKQ1.201202.002/vABM:user/release-keys, TCL/A600DL/Delhi_TF:11/RKQ1.201202.002/vABP:user/release-keys, and TCL/A600DL/Delhi_TF:11/RKQ1.201202.002/vABS:user/release-keys); TCL 10L (TCL/T770B/T1_LITE:10/QKQ1.200329.002/3CJ0:user/release-keys and TCL/T770B/T1_LITE:11/RKQ1.210107.001/8BIC:user/release-keys); Motorola Moto G Pure (motorola/ellis_trac/ellis:11/RRHS31.Q3-46-110-2/74844:user/release-keys, motorola/ellis_trac/ellis:11/RRHS31.Q3-46-110-7/5cde8:user/release-keys, motorola/ellis_trac/ellis:11/RRHS31.Q3-46-110-10/d67faa:user/release-keys, motorola/ellis_trac/ellis:11/RRHS31.Q3-46-110-13/b4a29:user/release-keys, motorola/ellis_trac/ellis:12/S3RH32.20-42-10/1c2540:user/release-keys, motorola/ellis_trac/ellis:12/S3RHS32.20-42-13-2-1/6368dd:user/release-keys, motorola/ellis_a/ellis:11/RRH31.Q3-46-50-2/20fec:user/release-keys, motorola/ellis_vzw/ellis:11/RRH31.Q3-46-138/103bd:user/release-keys, motorola/ellis_vzw/ellis:11/RRHS31.Q3-46-138-2/e5502:user/release-keys, and motorola/ellis_vzw/ellis:12/S3RHS32.20-42-10-14-2/5e0b0:user/release-keys); and Motorola Moto G Power (motorola/tonga_g/tonga:11/RRQ31.Q3-68-16-2/e5877:user/release-keys and motorola/tonga_g/tonga:12/S3RQS32.20-42-10-6/f876d3:user/release-keys). This malicious app reads from the ro.boot.wifimacaddr system property to indirectly obtain the Wi-Fi MAC address.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• https://media.defcon.org/DEF%20CON%2031/DEF%20CON%2031%20presentations/Ryan%20Johnson%20Mohamed%20Elsabagh%20Angelos%20Stavrou%20-%20Still%20Vulnerable%20Out%20of%20the%20Box%20Revisiting%20the%20Security%20of%20Prepaid%20Android%20Carrier%20Devices.pdf
• https://media.defcon.org/DEF%20CON%2031/DEF%20CON%2031%20presentations/Ryan%20Johnson%20Mohamed%20Elsabagh%20Angelos%20Stavrou%20-%20Still%20Vulnerable%20Out%20of%20the%20Box%20Revisiting%20the%20Security%20of%20Prepaid%20Android%20Carrier%20Devices.pdf