CVE-2018-15005

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.

Weakness

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Affected Software

Extended Description

Assuming a user with a given identity, authorization is the process of determining whether that user can access a given resource, based on the user’s privileges and any permissions or other access-control specifications that apply to the resource. When access control checks are not applied, users are able to access data or perform actions that they should not be allowed to perform. This can lead to a wide range of problems, including information exposures, denial of service, and arbitrary code execution.

Potential Mitigations

• Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
• Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
• For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
• One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/665.html

References

• http://www.securityfocus.com/bid/106361
• https://www.kryptowire.com/portal/android-firmware-defcon-2018/
• https://www.kryptowire.com/portal/wp-content/uploads/2018/12/DEFCON-26-Johnson-and-Stavrou-Vulnerable-Out-of-the-Box-An-Eval-of-Android-Carrier-Devices-WP-Updated.pdf