CVE-2019-2123 in Android
Summary
by MITRE
In execTransact of Binder.java in Android 7.1.1, 7.1.2, 8.0, 8.1, and 9, there is a possible local execution of arbitrary code in a privileged process due to a memory overwrite. 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 • 12/13/2023
The vulnerability identified as CVE-2019-2123 represents a critical memory corruption flaw within the Android operating system's Binder IPC mechanism, specifically affecting versions 7.1.1 through 9.0. This issue resides in the execTransact method of the Binder.java component, which serves as the fundamental communication layer between Android applications and system services. The Binder framework is essential for inter-process communication and handles privileged operations, making this vulnerability particularly dangerous as it operates within the core Android system architecture.
The technical root cause of CVE-2019-2123 stems from improper memory management during transaction execution within the Binder driver. When a transaction is processed through the execTransact method, a memory overwrite condition occurs that can be exploited to execute arbitrary code within the context of privileged processes. This memory corruption vulnerability allows an attacker to manipulate the execution flow of the Binder service, potentially enabling code injection attacks that bypass normal security boundaries. The flaw manifests as a buffer overflow or memory corruption issue that can be triggered through carefully crafted Binder transactions, leveraging the underlying memory management mechanisms of the Android system.
The operational impact of this vulnerability is severe, as it enables local privilege escalation without requiring any additional user interaction or elevated privileges. An attacker with local access to an Android device can exploit this weakness to gain system-level privileges, effectively bypassing the normal Android security model that separates applications from system services. This vulnerability affects the core Android framework components and can potentially allow attackers to execute malicious code with the highest level of system permissions, including access to sensitive user data, system files, and the ability to modify critical system functions. The exploitation occurs entirely within the kernel space of the Android operating system, making it particularly challenging to detect and prevent.
Mitigation strategies for CVE-2019-2123 should focus on immediate system updates and patches provided by Google, as this vulnerability was addressed through Android security updates released in 2019. Organizations and users must ensure their Android devices are updated to versions that include the patched Binder implementation, typically Android 7.1.2, 8.1, or 9.0 with the appropriate security patches. Additionally, implementing proper application sandboxing, monitoring for unusual Binder transaction patterns, and maintaining up-to-date security configurations can help reduce the attack surface. This vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and maps to ATT&CK technique T1068, which covers local privilege escalation through kernel exploits, making it a significant concern for mobile security professionals and system administrators managing Android environments.