CVE-2021-0534 in Android
Summary
by MITRE • 06/22/2021
In permission declarations of DeviceAdminReceiver.java, there is a possible lack of broadcast protection due to an insecure default value. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-170639543
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Analysis
by VulDB Data Team • 06/24/2021
The vulnerability described in CVE-2021-0534 resides within the Android operating system's permission declaration mechanisms, specifically within the DeviceAdminReceiver.java component. This issue represents a critical security flaw that undermines the integrity of Android's permission model and device administration controls. The vulnerability stems from an insecure default value in the broadcast protection configuration, which creates an exploitable weakness in the system's access control mechanisms.
The technical flaw manifests when device administrators register receivers without explicitly setting proper broadcast protection levels. In Android's security architecture, DeviceAdminReceiver components are designed to handle administrative commands and system-level operations through broadcast intents. When these receivers are configured with insufficient protection levels, they become susceptible to unauthorized access by malicious applications that may attempt to impersonate legitimate device administration services. This misconfiguration creates a pathway for privilege escalation attacks where unprivileged applications can potentially gain elevated system privileges.
The operational impact of this vulnerability is significant as it enables local privilege escalation without requiring any additional execution privileges or user interaction for exploitation. This means that any application running on the device with basic permissions could potentially leverage this flaw to gain device administrator privileges, effectively compromising the entire system. The lack of user interaction requirement makes this vulnerability particularly dangerous as it can be exploited automatically without any human intervention, and the attack surface extends to all Android 11 devices affected by this issue.
This vulnerability aligns with CWE-284, which addresses improper access control issues in software systems, specifically focusing on inadequate protection of broadcast receivers and their associated permissions. The flaw demonstrates a failure in proper privilege management and access control implementation within the Android framework, where default configurations do not adequately protect sensitive system components. From an ATT&CK perspective, this vulnerability maps to privilege escalation techniques under the T1068 category, specifically targeting the exploitation of insecure default configurations to gain elevated privileges.
The recommended mitigations for this vulnerability include implementing proper broadcast protection levels for all DeviceAdminReceiver components, ensuring that receivers are configured with appropriate security attributes such as android:permission or android:exported set to false. Android developers and security teams should conduct comprehensive code reviews to identify all instances where DeviceAdminReceiver components are declared without explicit protection settings. Additionally, system updates and patches should be deployed immediately to address the insecure default configurations, and organizations should implement monitoring to detect any unauthorized device administration activities that might indicate exploitation attempts. The vulnerability underscores the critical importance of secure default configurations in mobile operating systems and highlights the need for robust permission model enforcement throughout the Android ecosystem.