CVE-2020-0481 in Android
Summary
by MITRE • 12/15/2020
In AndroidManifest.xml, there is a possible permissions bypass. This could lead to local escalation of privilege allowing a non-system app to send a broadcast it shouldn't have permissions to send, with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-157472962
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Analysis
by VulDB Data Team • 12/18/2020
The vulnerability identified as CVE-2020-0481 represents a critical permissions bypass flaw within the Android operating system's manifest handling mechanism. This issue resides in the AndroidManifest.xml file processing where the system fails to properly validate broadcast permissions for non-system applications. The flaw allows malicious applications to circumvent intended security boundaries and send broadcasts that would normally require elevated permissions, effectively creating a pathway for unauthorized system interactions. The vulnerability specifically affects Android 11 and is tracked under Android ID A-157472962, highlighting its significance within the Android security framework.
The technical implementation of this vulnerability stems from improper validation of permission requirements within the AndroidManifest.xml parsing logic. When applications declare broadcast receivers or attempt to send broadcasts, the system should verify that the requesting application possesses the necessary permissions to perform such actions. However, in this case, the permission checking mechanism fails to properly enforce these security constraints, allowing applications to send broadcasts without appropriate authorization. This bypass occurs at the manifest parsing level where the system does not adequately verify whether the application attempting to send a broadcast has the required privileges, creating a direct pathway for privilege escalation.
The operational impact of this vulnerability is substantial as it enables local privilege escalation without requiring any user interaction or additional execution privileges. An attacker with a non-system application running on the device can exploit this flaw to send broadcasts that should be restricted to system-level applications only. This capability allows for potential system compromise, unauthorized data access, and interference with critical system processes. The vulnerability essentially undermines the fundamental security model of Android's permission system, where applications should be restricted to their declared capabilities and cannot exceed their granted permissions. The lack of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited automatically without any user awareness or consent.
This vulnerability maps to CWE-284, which describes improper access control mechanisms, and aligns with ATT&CK technique T1068, which covers local privilege escalation. The flaw represents a direct violation of Android's security model where applications should be sandboxed and restricted to their declared permissions. From a mitigation perspective, the primary solution involves applying the official Android security patches that address the manifest parsing logic and restore proper permission validation. System administrators should ensure all devices are updated to the latest Android 11 security patches, while developers should review their application manifests to ensure proper permission declarations and avoid relying on potentially vulnerable system behaviors. Additionally, organizations should implement monitoring solutions to detect unauthorized broadcast activities that could indicate exploitation attempts. The vulnerability highlights the critical importance of maintaining robust permission checking mechanisms and proper validation of application capabilities within mobile operating systems, particularly when dealing with inter-application communication and system-level operations.