NFC expanded as Near Field Communication, contains a set of protocols that allows Android devices to establish communication at a very shortest range. NFC used for contactless payments, pairing of devices, file sharing, and access control.
Nightwatch Cybersecurity noted that “NFC beaming of applications between devices using Android OS bypasses some security controls such as install unknown application,” this let a malicious phone or malicious payment terminal to install malware on the phone.
Starting from Android 8, users need to enable permission for individual apps to install unknown APK files. But if any system application will be “automatically whitelisted and would not prompt the user for this permission,” researchers said.
The NFC is one of the applications that have the permission to install other applications, if the NFC and Android Beam enabled devices taps any malicious phone or malicious NFC payment terminal, this let malware to be installed on the device bypassing “install unknown apps” prompt.
The “Install unknown apps” can be found under settings >> special access, by clicking “Install unknown apps” you can find which apps are allowed to perform this action.
Following steps to replicate a malicious drive-by install:
1. Setup two phones with NFC and Android beam enabled.
2 .Download any APK file on the “sender” phone (something like
this APK from GitHub).
3. Go to the file manager in the “sender” phone, tap the file and select “Share”. Then select “Android Beam” as the sharing method,
4. Bring two phones together and complete the transfer.
5. After this is done, go to the receiver phone, tap the “Beam completed” notification, and tap the file. It will skip directly to the install prompt, bypassing the “Install unknown apps” check.
Nightwatch Cybersecurity submitted the report to Google and the vulnerability is classified as high. The vulnerability was tested by researchers on Android 9 and Android 8.10.
Google released a fix and the users are recommended to update their devices, with the update “install unknown apps” permission in setting listed as “not allowed” to install applications.