CVE-2020-0345 in Android
Summary
by MITRE
In DocumentsUI, there is a possible permission bypass due to a confused deputy. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-144286721
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Analysis
by VulDB Data Team • 09/18/2020
The vulnerability identified as CVE-2020-0345 resides within the DocumentsUI component of Android operating systems, specifically affecting Android 11 and earlier versions. This flaw represents a critical security weakness that stems from a confused deputy problem, where a malicious application can exploit the system's permission model to gain unauthorized access to restricted resources. The vulnerability manifests through the DocumentsUI module's improper handling of inter-process communication and permission verification mechanisms, creating an opportunity for privilege escalation without requiring additional malicious code execution privileges.
The technical exploitation of this vulnerability occurs through a confused deputy scenario where a malicious application tricks the DocumentsUI component into performing actions on behalf of another application or user context. This confusion arises from the system's failure to properly validate the calling context and permissions when processing document-related operations. The vulnerability specifically affects how the system handles file access requests and document management operations within the user interface, allowing an attacker to bypass normal permission boundaries. According to CWE-284, this represents an improper access control issue where the system fails to properly enforce authorization checks, enabling unauthorized access to protected resources.
The operational impact of CVE-2020-0345 is significant as it enables local privilege escalation without requiring additional execution privileges or user interaction beyond the initial exploitation vector. An attacker with a malicious application installed on the device can leverage this vulnerability to gain elevated privileges and potentially access sensitive user data, system files, or other applications' resources. The vulnerability's exploitation requires user interaction to install the malicious application initially, but once installed, the attacker can perform privilege escalation attacks that bypass normal Android security boundaries. This represents a direct threat to the Android security model's integrity and could allow for complete system compromise.
Mitigation strategies for this vulnerability primarily involve applying the latest security patches and updates from Google, which address the confused deputy problem through improved permission validation and context checking mechanisms. Organizations should implement comprehensive mobile device management policies that enforce timely security updates and monitor for potential exploitation attempts. The vulnerability aligns with ATT&CK technique T1068, which covers "Local Port Configuration" and privilege escalation methods, and represents a classic example of how improper access control can be exploited for system compromise. Additionally, security teams should consider implementing runtime application protection measures and monitoring for suspicious file access patterns that might indicate exploitation attempts. The fix typically involves strengthening the permission checking logic in DocumentsUI to properly validate the calling application's identity and permissions before executing sensitive operations, effectively closing the confused deputy attack vector that enables the privilege escalation.