An issue was discovered on BLU R1 HD devices with Shanghai Adups software.

Summary

An issue was discovered on BLU R1 HD devices with Shanghai Adups software. The content provider named com.adups.fota.sysoper.provider.InfoProvider in the app with a package name of com.adups.fota.sysoper allows any app on the device to read, write, and delete files as the system user. In the com.adups.fota.sysoper app's AndroidManifest.xml file, it sets the android:sharedUserId attribute to a value of android.uid.system which makes it execute as the system user, which is a very privileged user on the device. This allows a third-party app to read, write, and delete files owned by the system user. The third-party app can modify the /data/system/users/0/settings_secure.xml file to add an app as a notification listener to be able to receive the text of notifications as they are received on the device. This also allows the /data/system/users/0/accounts.db to be read which contains authentication tokens for various accounts on the device. The third-party app can obtain privileged information and also modify files to obtain more privileges on the device.