CVE-2021-39628 in Android
Summary
by MITRE • 01/14/2022
In StatusBar.java, there is a possible disclosure of notification content on the lockscreen due to a logic error in the code. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-11Android ID: A-189575031
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Analysis
by VulDB Data Team • 01/19/2022
The vulnerability identified as CVE-2021-39628 resides within the StatusBar.java component of Android operating systems versions 10 and 11, representing a significant security flaw that compromises the confidentiality of notification content displayed on lockscreens. This issue stems from a fundamental logic error in the code implementation that fails to properly enforce access controls for sensitive notification data. The flaw specifically affects the notification management system's ability to distinguish between different user contexts and security levels when displaying information on locked devices.
The technical implementation error manifests in how the system evaluates notification visibility and access permissions during lockscreen display operations. When notifications are processed through the status bar component, the flawed logic does not adequately verify whether the current user context requires enhanced security measures or if the notification content should remain restricted to authenticated sessions. This oversight creates a scenario where sensitive information that should be protected from unauthorized viewing becomes accessible through the lockscreen interface without requiring any additional privileges or user interaction to exploit the vulnerability.
From an operational impact perspective, this vulnerability represents a critical information disclosure risk that could expose sensitive data such as messages, emails, calendar entries, or application notifications containing personal or confidential information. The lack of required user interaction for exploitation means that any attacker with physical access to a locked device could potentially access notification content without authentication. This risk is particularly concerning in enterprise environments where employees may receive notifications containing proprietary information, or in personal contexts where individuals may have access to sensitive communications through their devices.
The vulnerability aligns with CWE-200, which addresses "Information Exposure," and demonstrates how improper access control mechanisms can lead to unauthorized data disclosure. From an ATT&CK framework perspective, this issue maps to T1005, "Data from Local System," as it enables unauthorized access to data that would normally be protected by the device's security mechanisms. The flaw also relates to T1059, "Command and Scripting Interpreter," as it could potentially be leveraged as a stepping stone for further exploitation when combined with other vulnerabilities.
Security mitigations for this vulnerability should prioritize immediate patch deployment through official Android security updates, which would correct the logic error in the StatusBar.java implementation. Organizations should also implement additional protective measures such as enforcing strong screen lock mechanisms including biometric authentication, implementing device encryption policies, and configuring notification settings to limit sensitive information display on lockscreens. Network administrators should consider implementing device management policies that restrict notification visibility on locked devices and ensure that all Android devices receive timely security updates to address similar vulnerabilities in the notification subsystem.