CVE-2019-2215 in Android
Summary
by MITRE
A use-after-free in binder.c allows an elevation of privilege from an application to the Linux Kernel. No user interaction is required to exploit this vulnerability, however exploitation does require either the installation of a malicious local application or a separate vulnerability in a network facing application.Product: AndroidAndroid ID: A-141720095
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Analysis
by VulDB Data Team • 09/09/2024
The vulnerability described in CVE-2019-2215 represents a critical use-after-free flaw within the Android binder driver implementation that enables privilege escalation from user-space applications to kernel-level privileges. This vulnerability resides in the binder.c kernel source file and demonstrates how improper memory management can lead to severe security implications. The Android security team identified this issue as part of their ongoing efforts to maintain system integrity and protect against kernel-level exploits that could compromise the entire device.
The technical root cause of this vulnerability stems from a use-after-free condition where the binder driver fails to properly manage memory references during the handling of inter-process communication operations. When a malicious application interacts with the binder subsystem, it can manipulate the memory allocation and deallocation sequences in such a way that freed memory locations are accessed after being reallocated for other purposes. This memory corruption scenario creates opportunities for attackers to execute arbitrary code with kernel privileges, effectively bypassing the normal security boundaries that separate user applications from the kernel. The vulnerability operates at the kernel level within the Android operating system's IPC mechanism, making it particularly dangerous as it can be exploited without requiring user interaction or network connectivity.
The operational impact of this vulnerability is severe and far-reaching, as it allows for complete system compromise through local privilege escalation. An attacker who can install a malicious application on a device can leverage this vulnerability to gain root access to the kernel, enabling them to modify system files, extract sensitive data, install persistent backdoors, or disable security features. The lack of user interaction requirement makes this vulnerability particularly concerning for mobile devices where applications may be installed through various channels including official app stores, third-party sources, or through other attack vectors. The exploitation scenario requires either a malicious application installation or a separate network-facing vulnerability that could potentially be used to deliver the malicious payload, but once achieved, the attacker gains complete control over the kernel execution environment.
The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software development, and demonstrates how improper memory management practices can create security weaknesses in kernel-level code. From an attack framework perspective, this vulnerability maps to the privilege escalation techniques described in the MITRE ATT&CK framework under the privilege escalation tactics, specifically targeting kernel-level access. The Android-specific implementation of the binder driver, which serves as the primary IPC mechanism for Android applications, makes this vulnerability particularly impactful as it affects the fundamental communication infrastructure of the operating system. Security researchers have noted that such kernel-level vulnerabilities often require complex exploitation techniques and are typically discovered through advanced fuzzing methodologies or formal verification approaches.
Mitigation strategies for CVE-2019-2215 primarily focus on patching the underlying kernel implementation and implementing additional security controls within the Android framework. Google released security patches for affected Android versions that address the memory management issues in the binder driver and prevent the use-after-free condition from being exploitable. Organizations should ensure that all Android devices are updated to the latest security patches, particularly those addressing the Android ID A-141720095. Additional mitigations include implementing application sandboxing measures, monitoring for suspicious IPC activities, and maintaining strict controls over application installation sources. The vulnerability underscores the importance of proper memory management practices in kernel code development and highlights the need for continuous security auditing of core operating system components. Device manufacturers and security teams should also consider implementing runtime protections that can detect and prevent exploitation attempts targeting similar memory corruption vulnerabilities.