CVE-2018-9471 in Android
Summary
by MITRE • 11/20/2024
In the deserialization constructor of NanoAppFilter.java, there is a possible loss of data due to type confusion. This could lead to local escalation of privilege in the system server with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 12/18/2024
The vulnerability identified as CVE-2018-9471 resides within the deserialization process of the NanoAppFilter.java component, representing a critical type confusion flaw that enables unauthorized privilege escalation. This issue manifests during the object deserialization constructor execution where improper type handling creates conditions for data loss and system compromise. The vulnerability operates at a fundamental level within the Android system architecture, specifically targeting the system server's security boundaries. The type confusion occurs when the deserialization logic fails to properly validate or enforce type integrity during object reconstruction, allowing malicious data to be interpreted with incorrect type information. This misalignment between expected and actual data types creates exploitable conditions that can be leveraged by malicious actors to manipulate system behavior.
The technical exploitation of this vulnerability enables local privilege escalation without requiring any user interaction or additional execution privileges, making it particularly dangerous in system server contexts. The flaw operates through a deserialization attack vector where crafted malicious input can cause the system to interpret data incorrectly during the reconstruction phase. The vulnerability's impact extends beyond simple data corruption as it directly compromises the system server's integrity, potentially allowing attackers to execute arbitrary code with elevated privileges. This type confusion vulnerability aligns with CWE-471, which specifically addresses the weakness of using an incorrect variable type in a function call or assignment, and represents a classic example of how improper type validation during deserialization can lead to severe security consequences.
The operational implications of CVE-2018-9471 are significant for Android system security, as it provides a path for attackers to gain elevated privileges within the system server environment. The lack of user interaction requirements means that exploitation can occur automatically, making this vulnerability particularly dangerous in environments where system integrity is paramount. The vulnerability affects the core deserialization mechanism that handles NanoAppFilter objects, which are commonly used in Android applications for filtering and processing data. Attackers can leverage this flaw to bypass existing security controls and potentially gain access to sensitive system resources or execute unauthorized operations. The privilege escalation occurs because the system server processes the maliciously crafted serialized data without proper validation, leading to incorrect type interpretation and subsequent system compromise.
Security mitigations for this vulnerability should focus on implementing robust type validation during deserialization processes, particularly within system server components. The recommended approach involves strengthening the deserialization constructor in NanoAppFilter.java to enforce strict type checking and validation before object reconstruction occurs. Organizations should implement proper input sanitization and type integrity checks that prevent type confusion scenarios from occurring. The mitigation strategy should also include regular security updates and patches to address the underlying deserialization flaw, as well as implementing runtime monitoring to detect anomalous deserialization patterns. Additionally, the security architecture should incorporate defensive programming practices that prevent improper type handling during object reconstruction, aligning with ATT&CK technique T1059.007 for command and script injection through deserialization vulnerabilities. System administrators should also consider implementing least privilege principles and access controls to limit the potential impact of successful exploitation attempts, while maintaining comprehensive logging and monitoring capabilities to detect any suspicious deserialization activities.