CVE-2021-0331 in Android
Summary
by MITRE • 02/10/2021
In onCreate of NotificationAccessConfirmationActivity.java, there is a possible overlay attack due to an insecure default value. This could lead to local escalation of privilege and notification access with User execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-9 Android-10 Android-11 Android-8.1Android ID: A-170731783
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Analysis
by VulDB Data Team • 02/27/2021
The vulnerability identified as CVE-2021-0331 resides within the NotificationAccessConfirmationActivity.java component of Android operating systems spanning versions 8.1 through 11. This flaw represents a critical security weakness that enables malicious actors to exploit overlay attack vectors through insecure default configurations. The vulnerability specifically manifests during the onCreate method execution where the application fails to properly validate or secure default settings that govern notification access permissions. Such insecure default values create an exploitable condition that allows unauthorized applications to potentially gain elevated privileges and access notification data from other applications.
The technical implementation of this vulnerability stems from inadequate input validation and security hardening within the Android notification access framework. When users interact with notification access confirmation dialogs, the system's default behavior fails to properly enforce security boundaries, creating opportunities for malicious applications to overlay legitimate interfaces and deceive users into granting unwanted permissions. This represents a classic case of insufficient privilege separation and inadequate security context management that aligns with CWE-284 Access Control Issues and CWE-352 Cross-Site Request Forgery patterns. The vulnerability operates under the premise that user interaction is required for exploitation, making it particularly dangerous as it leverages social engineering elements to bypass traditional security controls.
From an operational impact perspective, this vulnerability creates significant risk for Android users as it enables local escalation of privilege attacks that can result in unauthorized access to sensitive notification data. Notification access provides attackers with potentially sensitive information including messages, alerts, and contextual data from other applications that may contain personal information, financial details, or corporate secrets. The requirement for user interaction makes this vulnerability particularly insidious as it can be exploited through deceptive user interface manipulation where attackers present convincing fake confirmation dialogs to trick users into granting notification access to malicious applications. This attack vector directly maps to ATT&CK technique T1546.001 for privilege escalation and T1059 for user interaction exploitation.
The mitigation strategies for CVE-2021-0331 primarily focus on implementing proper input validation and secure default configurations within Android notification access frameworks. System administrators and developers should ensure that all notification access confirmation dialogs properly validate user intent and enforce strict security boundaries. The Android security model should be enhanced to prevent overlay attacks through improved window management and security context validation. Users should be educated about the risks of granting notification access permissions and should be vigilant when interacting with notification access confirmation dialogs. Additionally, regular security updates and patches should be implemented to address the underlying insecure default configurations that enable this vulnerability. The fix typically involves modifying the onCreate method to properly initialize security parameters and validate user interactions before granting notification access permissions, thereby preventing unauthorized privilege escalation through overlay attack techniques.