CVE-2020-0409 in Android
Summary
by MITRE • 11/10/2020
In create of FileMap.cpp, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-8.0 Android-8.1 Android-9Android ID: A-156997193
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Analysis
by VulDB Data Team • 12/04/2020
The vulnerability identified as CVE-2020-0409 represents a critical integer overflow condition within the file mapping component of Android's system architecture. This flaw exists in the create function of FileMap.cpp, where improper handling of integer arithmetic creates opportunities for memory corruption. The vulnerability specifically manifests as an out-of-bounds write condition that can be exploited to gain elevated privileges on affected Android devices. The integer overflow occurs during the calculation of memory allocation sizes, where the system fails to properly validate or check for overflow conditions before proceeding with memory operations.
The technical implementation of this vulnerability stems from inadequate input validation within the file mapping subsystem that processes memory allocation requests. When the system processes file mapping operations, it performs arithmetic calculations to determine buffer sizes and memory allocation requirements. The integer overflow occurs when these calculations exceed the maximum representable value for the integer type being used, causing the subsequent memory allocation to be insufficiently sized. This results in memory being written beyond the intended boundaries, potentially overwriting adjacent memory regions including critical system structures or privilege control mechanisms.
The operational impact of CVE-2020-0409 extends significantly beyond typical local privilege escalation scenarios due to its inherent characteristics within the Android operating system. This vulnerability affects multiple Android versions including Android 8.0, 8.1, 9, and 10, representing a substantial attack surface across the Android ecosystem. The exploitation requires no additional execution privileges beyond what is normally available to a local user, making it particularly dangerous as it can be leveraged by malicious applications or processes already present on the device. The lack of user interaction requirements means that exploitation can occur automatically without any explicit user consent or action, potentially allowing attackers to silently escalate privileges and gain unauthorized access to sensitive system functions.
This vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and demonstrates characteristics consistent with ATT&CK technique T1068, which involves exploiting legitimate credentials or privileges to escalate access. The flaw represents a classic example of how memory safety issues in system-level components can be exploited to achieve privilege escalation, particularly within mobile operating system environments where such vulnerabilities can be leveraged to gain access to device-level functionality. The attack vector primarily targets the Android system's file mapping services, which are fundamental components used throughout the operating system for memory management and file handling operations.
Mitigation strategies for CVE-2020-0409 should prioritize immediate patch deployment through official Android security updates provided by Google and device manufacturers. Organizations and users should ensure all affected Android devices receive the latest security patches, particularly those addressing memory management and privilege escalation vulnerabilities. System administrators should implement monitoring for unusual privilege escalation activities and consider device hardening measures that restrict unnecessary file mapping operations. Additionally, security researchers should conduct vulnerability assessments of custom Android implementations and third-party applications that may interact with file mapping components to identify potential exploitation vectors. The vulnerability underscores the critical importance of proper integer overflow protection in system-level code and demonstrates how seemingly minor coding errors can have significant security implications across entire operating system families.