CVE-2022-20146 in Android
Summary
by MITRE • 06/15/2022
In uploadFile of FileUploadServiceImpl.java, there is a possible incorrect file access due to a confused deputy. This could lead to local information disclosure of private files with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-211757677References: N/A
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Analysis
by VulDB Data Team • 06/15/2022
The vulnerability identified as CVE-2022-20146 represents a critical confused deputy problem within the Android kernel's file upload functionality. This flaw exists in the uploadFile method of FileUploadServiceImpl.java, where improper file access controls create opportunities for unauthorized data disclosure. The confused deputy vulnerability occurs when a legitimate process is tricked into performing operations on behalf of another entity, effectively bypassing normal access controls and security boundaries. This particular weakness stems from inadequate validation of file access permissions during the upload process, allowing malicious actors to potentially access private files that should otherwise remain protected.
The technical implementation of this vulnerability involves a specific flaw in how the Android kernel handles file access during upload operations. When the uploadFile method processes incoming files, it fails to properly validate or sanitize the file access context, creating a scenario where a confused deputy attack can succeed. This misconfiguration allows for local information disclosure without requiring any additional execution privileges or user interaction, making the vulnerability particularly dangerous as it can be exploited silently in the background. The flaw specifically affects the Android kernel version and is tracked under Android ID A-211757677, indicating its deep integration with core system components.
From an operational perspective, this vulnerability poses significant risks to Android device security and user privacy. The local information disclosure aspect means that attackers can potentially access sensitive files stored on the device without requiring elevated privileges or user consent. This could include personal documents, photos, messages, or other private data that should remain protected by the system's access controls. The fact that no user interaction is required for exploitation makes this vulnerability particularly concerning as it can be leveraged automatically by malware or malicious applications already present on the device. The attack surface extends to any application or service that utilizes the vulnerable file upload functionality, potentially affecting a wide range of Android applications and system services.
The vulnerability aligns with CWE-285 (Improper Authorization) and CWE-276 (Incorrect Default Permissions) classifications, as it represents a failure in proper access control mechanisms and incorrect handling of file permissions. From the ATT&CK framework perspective, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1005 (Data from Local System) techniques, as it enables unauthorized access to system data without requiring command execution. The attack chain typically involves exploiting the confused deputy scenario to gain access to private files, which can then be exfiltrated or used for further exploitation. Organizations should implement immediate mitigations including kernel updates, enhanced file access controls, and monitoring for unauthorized file access patterns to prevent exploitation of this vulnerability.