Vulnerabilities

The Coolpad Canvas device with a build fingerprint of Coolpad/cp3636a/cp3636a:7.0/NRD90M/093031423:user/release-keys contains a platform app with a package name of com.qualcomm.qti.modemtestmode (versionCode=24, versionName=7.0) that contains an exported service app component named com.qualcomm.qti.modemtestmode.MbnTestService that allows any app on the device to set certain system properties as the com.android.phone user. When an app sets the persist.service.logr.enable system property to a value of 1, an app with a package name of com.yulong.logredirect (versionCode=20160622, versionName=5.25_20160622_01) will start writing the system-wide logcat log, kernel log, and a tcpdump network traffic capture to external storage. Furthermore, on the Coolpad Canvas device, the com.android.phone app writes the destination phone number and body of the text message for outgoing text messages. A notification when logging can be avoided if the log is enabled after device startup and disabled prior to device shutdown by setting the system properties using the exported interface of the com.qualcomm.qti.modemtestmode app. Any app with the READ_EXTERNAL_STORAGE permission can access the log files.

The ZTE Blade Vantage Android device with a build fingerprint of ZTE/Z839/sweet:7.1.1/NMF26V/20180120.095344:user/release-keys, the ZTE Blade Spark Android device with a build fingerprint of ZTE/Z971/peony:7.1.1/NMF26V/20171129.143111:user/release-keys, the ZTE ZMAX Pro Android device with a build fingerprint of ZTE/P895T20/urd:6.0.1/MMB29M/20170418.114928:user/release-keys, and the ZTE ZMAX Champ Android device with a build fingerprint of ZTE/Z917VL/fortune:6.0.1/MMB29M/20170327.120922:user/release-keys contain a pre-installed platform app with a package name of com.android.modem.service (versionCode=25, versionName=7.1.1; versionCode=23, versionName=6.0.1) that exports an interface to any app on co-located on the device. Using the exported interface of the com.android.modem.service app, any app can enable and obtain certain log files (modem and logcat) without the appropriate corresponding access permissions. The modem logs contain the phone number and full text body of incoming and outgoing text messages in binary format. In addition, the modem log contains the phone numbers for both incoming and outgoing phone calls. The system-wide logcat logs (those obtained via the logcat binary) tend to contain sensitive user data. Third-party apps are prevented from directly reading the system-wide logcat logs. The capability to read from the system-wide logcat logs is only available to pre-installed system apps and platform apps. The modem log and/or logcat log, once activated, get written to external storage (SD card). An app aware of this vulnerability can enable the logs, parse them for relevant data, and exfiltrate them from the device. The modem log and logcat log are inactive by default, but a third-party app with no permissions can activate them, although the app will need to be granted the READ_EXTERNAL_STORAGE permission to access them.

The Leagoo Z5C Android device with a build fingerprint of sp7731c_1h10_32v4_bird:6.0/MRA58K/android.20170629.214736:user/release-keys contains a pre-installed app with a package name of com.android.messaging (versionCode=1000110, versionName=1.0.001, (android.20170630.092853-0)) containing an exported content provider named com.android.messaging.datamodel.MessagingContentProvider. Any app co-located on the device can read the most recent text message from each conversation. That is, for each phone number where the user has either sent or received a text message from, a zero-permission third-party app can obtain the body of the text message, phone number, name of the contact (if it exists), and a timestamp for the most recent text message of each conversation. As the querying of the vulnerable content provider app component can be performed silently in the background, a malicious app can continuously monitor the content provider to see if the current message in each conversation has changed to obtain new text messages.

The MXQ TV Box 4.4.2 Android device with a build fingerprint of MBX/m201_N/m201_N:4.4.2/KOT49H/20160106:user/test-keys contains the Android framework with a package name of android (versionCode=19, versionName=4.4.2-20170213) that contains an exported broadcast receiver application component that, when called, will make the device inoperable. The vulnerable component named com.android.server.SystemRestoreReceiver will write a value of --restore_system\n--locale=

The ASUS ZenFone 3 Max Android device with a build fingerprint of asus/US_Phone/ASUS_X008_1:7.0/NRD90M/US_Phone-14.14.1711.92-20171208:user/release-keys contains a pre-installed app with a package name of com.asus.loguploader (versionCode=1570000275, versionName=7.0.0.55_170515). This app contains an exported service app component named com.asus.loguploader.LogUploaderService that, when accessed with a particular action string, will write a bugreport (kernel log, logcat log, and the state of system services including the text of active notifications), Wi-Fi Passwords, and other system data to external storage (sdcard). Any app with the READ_EXTERNAL_STORAGE permission on this device can read this data from the sdcard after it has been dumped there by the com.asus.loguploader. Third-party apps are not allowed to directly create a bugreport or access the user's stored wireless network credentials.

The Leagoo Z5C Android device with a build fingerprint of sp7731c_1h10_32v4_bird:6.0/MRA58K/android.20170629.214736:user/release-keys contains a pre-installed app with a package name of com.android.messaging (versionCode=1000110, versionName=1.0.001, (android.20170630.092853-0)) with an exported broadcast receiver app component named com.android.messaging.trackersender.TrackerSender. Any app co-located on the device, even one with no permissions, can send a broadcast intent with certain embedded data to the exported broadcast receiver application component that will result in the programmatic sending of a text message where the phone number and body of the text message is controlled by the attacker.

The Leagoo Z5C Android device with a build fingerprint of sp7731c_1h10_32v4_bird:6.0/MRA58K/android.20170629.214736:user/release-keys contains a pre-installed platform app with a package name of com.android.settings (versionCode=23, versionName=6.0-android.20170630.092853) that contains an exported broadcast receiver that allows any app co-located on the device to programmatically initiate a factory reset. In addition, the app initiating the factory reset does not require any permissions. A factory reset will remove all user data and apps from the device. This will result in the loss of any data that have not been backed up or synced externally. The capability to perform a factory reset is not directly available to third-party apps (those that the user installs themselves with the exception of enabled Mobile Device Management (MDM) apps), although this capability can be obtained by leveraging an unprotected app component of a pre-installed platform app.

The Leagoo P1 Android device with a build fingerprint of sp7731c_1h10_32v4_bird:6.0/MRA58K/android.20170629.214736:user/release-keys contains a hidden root privilege escalation capability to achieve command execution as the root user. They have made modifications that allow a user with physical access to the device to obtain a root shell via ADB by modifying read-only system properties at runtime. Specifically, modifying the ro.debuggable and the ro.secure system properties to a certain value and then restarting the ADB daemon allows for a root shell to be obtained via ADB.

The ZTE ZMAX Champ Android device with a build fingerprint of ZTE/Z917VL/fortune:6.0.1/MMB29M/20170327.120922:user/release-keys contains a pre-installed platform app with a package name of com.zte.zdm.sdm (versionCode=31, versionName=V5.0.3) that contains an exported broadcast receiver app component named com.zte.zdm.VdmcBroadcastReceiver that allows any app co-located on the device to programmatically initiate a factory reset. In addition, the app initiating the factory reset does not require any permissions. A factory reset will remove all user data and apps from the device. This will result in the loss of any data that have not been backed up or synced externally. The capability to perform a factory reset is not directly available to third-party apps (those that the user installs themselves with the exception of enabled Mobile Device Management (MDM) apps), although this capability can be obtained by leveraging an unprotected app component of a pre-installed platform app.

The ZTE ZMAX Champ Android device with a build fingerprint of ZTE/Z917VL/fortune:6.0.1/MMB29M/20170327.120922:user/release-keys contains a pre-installed platform app with a package name of com.android.zte.hiddenmenu (versionCode=23, versionName=6.0.1) that contains an exported broadcast receiver app component named com.android.zte.hiddenmenu.CommandReceiver that is accessible to any app co-located on the device. This app component, when it receives a broadcast intent with a certain action string, will write a non-standard (i.e., not defined in Android Open Source Project (AOSP) code) command to the /cache/recovery/command file to be executed in recovery mode. Once the device boots into recovery mode, it will crash, boot into recovery mode, and crash again. This crash loop will keep repeating, which makes the device unusable. There is no way to boot into an alternate mode once the crash loop starts.

The MXQ TV Box 4.4.2 Android device with a build fingerprint of MBX/m201_N/m201_N:4.4.2/KOT49H/20160106:user/test-keys contains the Android framework with a package name of android (versionCode=19, versionName=4.4.2-20170213) that dynamically registers a broadcast receiver app component named com.android.server.MasterClearReceiver instead of statically registering it in the AndroidManifest.xml file of the core Android package, as done in Android Open Source Project (AOSP) code for Android 4.4.2. The dynamic-registration of the MasterClearReceiver broadcast receiver app component is not protected with the android.permission.MASTER_CLEAR permission during registration, so any app co-located on the device, even those without any permissions, can programmatically initiate a factory reset of the device. A factory reset will remove all user data and apps from the device. This will result in the loss of any data that have not been backed up or synced externally. The capability to perform a factory reset is not directly available to third-party apps (those that the user installs themselves with the exception of enabled Mobile Device Management (MDM) apps), although this capability can be obtained by leveraging an unprotected app component of core Android process.

The ASUS ZenFone 3 Max Android device with a build fingerprint of asus/US_Phone/ASUS_X008_1:7.0/NRD90M/US_Phone-14.14.1711.92-20171208:user/release-keys contains a pre-installed platform app with a package name of com.asus.dm (versionCode=1510500200, versionName=1.5.0.40_171122) has an exposed interface in an exported service named com.asus.dm.installer.DMInstallerService that allows any app co-located on the device to use its capabilities to download an arbitrary app over the internet and install it. Any app on the device can send an intent with specific embedded data that will cause the com.asus.dm app to programmatically download and install the app. For the app to be downloaded and installed, certain data needs to be provided: download URL, package name, version name from the app's AndroidManifest.xml file, and the MD5 hash of the app. Moreover, any app that is installed using this method can also be programmatically uninstalled using the same unprotected component named com.asus.dm.installer.DMInstallerService.