CVE-2021-0769 in Android
Summary
by MITRE • 12/15/2021
In onCreate of AllowBindAppWidgetActivity.java, there is a possible bypass of user interaction requirements due to unclear UI. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-12Android ID: A-184676316
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Analysis
by VulDB Data Team • 12/22/2021
The vulnerability identified as CVE-2021-0769 resides within the Android framework's AllowBindAppWidgetActivity.java component, representing a critical security flaw that undermines the system's user interaction requirements for app widget binding operations. This vulnerability specifically affects Android 12 systems and is catalogued under Android ID A-184676316, demonstrating the severity of the issue within the mobile operating system's security architecture. The flaw manifests in the onCreate method where the user interface logic fails to properly enforce the necessary user interaction protocols that should govern app widget binding processes.
The technical implementation of this vulnerability stems from an unclear user interface design that allows malicious applications to potentially bypass the intended user consent mechanisms. When an application attempts to bind an app widget, the system should require explicit user interaction to confirm the operation. However, the current implementation suffers from ambiguous UI state management that could permit unauthorized binding operations without proper user acknowledgment. This design flaw creates a pathway where attacker-controlled applications can manipulate the binding process to occur automatically, circumventing the security controls meant to protect users from unintended widget installations.
From an operational perspective, this vulnerability enables local privilege escalation without requiring additional execution privileges, making it particularly dangerous within the Android security model. The attack vector relies on user interaction for exploitation, meaning that while an attacker cannot automatically trigger the vulnerability, they can exploit it through social engineering or by pre-positioning malicious applications. The security implications extend beyond simple widget manipulation, as app widgets can serve as entry points for more sophisticated attacks due to their privileged access to system resources and user data. The vulnerability's classification aligns with CWE-691, which addresses insufficient control over uncontrolled inputs, and its exploitation pattern matches techniques described in the ATT&CK framework under privilege escalation tactics.
The mitigation strategies for this vulnerability involve both immediate system-level patches and architectural improvements to the user interface validation mechanisms. Android security updates should address the UI state management in AllowBindAppWidgetActivity.java to ensure that all widget binding operations require explicit user confirmation before proceeding. Security researchers and device manufacturers must implement proper input validation and user interaction verification protocols to prevent automatic binding operations from occurring without user consent. Organizations should also consider implementing additional monitoring for unusual widget binding activities and ensure that users are educated about the potential risks of installing applications from untrusted sources. The vulnerability underscores the critical importance of maintaining robust user interaction requirements in mobile operating systems, particularly for operations that involve system-level resource access and user data exposure.