CVE-2018-9375 in Android
Summary
by MITRE • 01/18/2025
In multiple functions of UserDictionaryProvider.java, there is a possible way to add and delete words in the user dictionary due to a confused deputy. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 02/19/2025
The vulnerability identified as CVE-2018-9375 resides within the UserDictionaryProvider.java component of Android systems, representing a critical confused deputy problem that enables unauthorized privilege escalation. This flaw manifests in multiple functions where the system fails to properly validate the identity of the calling process, creating a scenario where malicious actors can manipulate the user dictionary through deceptive means. The vulnerability operates at the core level of Android's text input system, specifically affecting how the system handles user dictionary modifications and deletions. The confused deputy aspect arises when the system incorrectly trusts the identity of a process that should not have elevated privileges, allowing unauthorized modifications to the dictionary files that typically require system-level access.
The technical implementation of this vulnerability stems from inadequate access control mechanisms within the Android framework's content provider architecture. When user dictionary operations are performed, the system should verify that the requesting process has proper authorization to modify dictionary entries. However, the flaw allows processes with limited privileges to masquerade as legitimate system components, bypassing normal security checks. This confusion occurs during the authentication and authorization phases where the system fails to properly validate the calling context, leading to improper privilege delegation. The vulnerability affects the underlying Android framework's ability to maintain proper access controls, particularly in scenarios where user dictionary management should require elevated permissions but does not enforce them correctly.
The operational impact of CVE-2018-9375 extends beyond simple dictionary manipulation, creating a pathway for local privilege escalation that can be exploited without requiring any user interaction or additional execution privileges. An attacker with access to a standard application context can leverage this vulnerability to gain elevated system privileges, potentially enabling them to modify system files, access sensitive data, or establish persistent access to the device. The implications are particularly severe because the vulnerability operates silently in the background, making detection difficult while providing attackers with a reliable method to escalate their privileges within the Android environment. This type of vulnerability aligns with CWE-284 (Improper Access Control) and represents a classic example of how improper privilege management can lead to system compromise, as documented in the MITRE ATT&CK framework under privilege escalation techniques.
Mitigation strategies for this vulnerability require immediate system updates from device manufacturers and network administrators to ensure all affected Android versions receive the necessary security patches. The fix typically involves implementing proper access control validation within the UserDictionaryProvider component, ensuring that all dictionary modification operations properly verify the calling process identity before granting access. Organizations should also consider implementing additional monitoring mechanisms to detect unauthorized dictionary modifications and maintain strict control over application permissions. The vulnerability highlights the importance of proper privilege separation and access control implementation in mobile operating systems, as outlined in security best practices from NIST and other cybersecurity frameworks. Regular security audits of content provider implementations and proper validation of process identities should become standard practice to prevent similar confused deputy scenarios in future system development.