CVE-2021-0604 in Android
Summary
by MITRE • 07/15/2021
In generateFileInfo of BluetoothOppSendFileInfo.java, there is a possible way to share private files over Bluetooth due to a confused deputy. This could lead to local information disclosure with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-9 Android-10 Android-11 Android-8.1Android ID: A-179910660
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Analysis
by VulDB Data Team • 07/18/2021
The vulnerability identified as CVE-2021-0604 resides within the Bluetooth file sharing functionality of Android operating systems across multiple versions including Android 8.1, 9, 10, and 11. This flaw exists in the generateFileInfo method of the BluetoothOppSendFileInfo.java component, which handles the preparation of file information for Bluetooth transmission. The issue stems from a confused deputy problem where the system fails to properly validate file access permissions during the Bluetooth sharing process, creating a pathway for unauthorized file access.
The technical implementation flaw occurs when the Bluetooth OPP (Object Push Profile) service processes file information for transmission. The confused deputy vulnerability arises because the system does not adequately verify whether the requesting application has proper authorization to access the files being shared via Bluetooth. This misconfiguration allows malicious applications or attackers to manipulate the file sharing process and potentially access private files that should remain protected. The vulnerability specifically affects the permission validation mechanism within the Bluetooth file transfer workflow, where the system trusts the file information provided by the application without sufficient verification of the actual file access rights.
The operational impact of this vulnerability is significant as it enables local information disclosure without requiring any additional execution privileges or root access. An attacker needs only user interaction to exploit this weakness, making it particularly dangerous in environments where users might unknowingly trigger the malicious file sharing process. The vulnerability essentially allows for unauthorized access to private files stored on the device, potentially exposing sensitive data such as personal documents, photos, messages, or other confidential information. This represents a direct violation of the principle of least privilege and could be leveraged to compromise user privacy and data confidentiality.
The security implications extend beyond simple file access, as this vulnerability aligns with CWE-284 (Improper Access Control) and can be categorized under ATT&CK technique T1059 (Command and Scripting Interpreter) when exploited for broader system compromise. The vulnerability's classification as a confused deputy problem (CWE-285) indicates that the system's trust relationship has been misconfigured, allowing an attacker to manipulate the system's behavior through legitimate but improperly validated file sharing operations. Organizations should consider this vulnerability as part of their broader security posture assessment, particularly in environments where Android devices handle sensitive information. The recommended mitigations include applying the latest security patches from Google, implementing proper application sandboxing, and conducting regular security audits of Bluetooth file sharing implementations. Additionally, users should be educated about the risks of sharing files via Bluetooth and the importance of verifying application permissions before granting access to sensitive data.