CVE-2019-2159 in Android
Summary
by MITRE
In libxaac there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution with no additional execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-112707186
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Analysis
by VulDB Data Team • 09/11/2020
The vulnerability identified as CVE-2019-2159 resides within the libxaac library component of Android systems, specifically affecting Android 10 installations. This issue represents a critical security flaw that manifests as an out-of-bounds write condition, a type of memory corruption vulnerability that falls under the CWE-787 category. The vulnerability stems from the absence of proper bounds checking within the audio decoding functionality, which processes advanced audio coding format files. When an attacker crafts malicious audio content specifically designed to exploit this weakness, the missing validation allows data to be written beyond the allocated memory boundaries of the affected buffer.
The exploitation of this vulnerability requires user interaction, meaning that a malicious actor must convince a victim to play or process a specially crafted audio file. This interaction requirement places the vulnerability in the context of social engineering attacks where users might encounter compromised audio content through various channels such as messaging applications, media sharing platforms, or malicious websites. The attack vector typically involves the victim opening or playing a specially crafted audio file that triggers the vulnerable code path within libxaac. This type of attack aligns with ATT&CK technique T1203, which covers Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute code on target systems.
The potential impact of successful exploitation extends to full remote code execution capabilities without requiring any additional privileges or user context switching. This means that once the malicious audio file is processed, the attacker gains the ability to execute arbitrary code within the context of the affected application or system services. The vulnerability's severity is amplified by its location within the audio processing pipeline, which typically runs with elevated privileges to handle media decoding tasks. This privileged execution context allows the attacker to potentially escalate their control over the device, access sensitive data, modify system files, or establish persistence mechanisms. The vulnerability affects the Android operating system's multimedia framework, specifically targeting the advanced audio coding decoding capabilities that are integral to modern smartphone functionality.
Mitigation strategies for CVE-2019-2159 primarily involve applying the security patches released by Google as part of their regular Android security updates. Organizations and users should ensure that their Android devices are updated to the latest security patches, particularly those released in the 2019-08-05 security bulletin. System administrators should implement proactive monitoring to identify devices running vulnerable versions of Android and prioritize their update schedules. Additionally, implementing network-level controls to filter potentially malicious audio content and educating users about the risks of opening untrusted media files can provide additional defense layers. The vulnerability also highlights the importance of input validation and bounds checking in multimedia processing libraries, as demonstrated by the CWE-129 standard that emphasizes the need for proper validation of array indices and buffer sizes. Organizations should conduct regular security assessments of their Android-based systems to identify similar vulnerabilities in other components of their multimedia frameworks and ensure comprehensive patch management programs are in place to address such issues promptly.