CVE-2019-9438 in Android
Summary
by MITRE
In the Package Manager service, there is a possible information disclosure due to a confused deputy. This could lead to local disclosure of information about installed packages for other users with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-77821568
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/13/2020
The vulnerability identified as CVE-2019-9438 represents a critical information disclosure flaw within Android's Package Manager service that exploits a confused deputy scenario. This vulnerability resides in the core system component responsible for managing application packages and their installation processes. The confused deputy problem occurs when a system service incorrectly interprets or processes requests from untrusted sources, leading to unauthorized information access. In this specific case, the Package Manager service fails to properly validate the identity of requesting processes, allowing malicious actors to potentially access package information belonging to other users on the same device.
The technical implementation of this vulnerability stems from insufficient access control mechanisms within the Package Manager's inter-process communication framework. When applications or system services attempt to query package information through the Package Manager, the service does not adequately verify the requesting entity's privileges or identity. This weakness creates an opportunity for local attackers to exploit the service by crafting specific requests that bypass normal access controls. The vulnerability specifically affects Android 10 and is tracked under Android ID A-77821568, indicating its classification within Google's internal vulnerability tracking system. No user interaction is required for exploitation, making this particularly concerning as it can be triggered automatically without any deliberate action from the end user.
The operational impact of CVE-2019-9438 extends beyond simple information disclosure, as it provides attackers with detailed insights into the package ecosystem of other users. This information can include installed applications, package names, version details, and potentially other metadata that could be leveraged for further attacks. The local nature of this vulnerability means that attackers do not require network access or additional privileges beyond what is already available to them, making it particularly dangerous in multi-user environments or when applications are running with elevated privileges. This type of information disclosure aligns with CWE-200 (Information Exposure) and can be categorized under the ATT&CK technique T1083 (File and Directory Discovery) when exploited for reconnaissance purposes. The vulnerability essentially allows for lateral information gathering that could be used to identify potential attack vectors or targets within the system.
Mitigation strategies for this vulnerability primarily involve implementing proper access control validation within the Package Manager service. Android security patches addressed this issue by strengthening the authentication mechanisms and ensuring that all requests to the Package Manager are properly validated against the requesting process's identity and privileges. System administrators should ensure that all Android devices are updated to the latest security patches, particularly those released in the Q2 2019 security updates. Organizations should also implement monitoring solutions that can detect unusual patterns of package information requests, as this could indicate exploitation attempts. The fix demonstrates the importance of proper privilege separation and access control validation, aligning with security best practices outlined in the OWASP Top 10 and NIST cybersecurity frameworks. Regular security audits of system services and inter-process communication mechanisms should be conducted to identify similar confused deputy vulnerabilities that could potentially compromise system integrity and user privacy.