CVE-2019-9307 in Android
Summary
by MITRE
In libAACdec, there is a possible out of bounds write due to an integer overflow. 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-112661893
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability CVE-2019-9307 resides within the libAACdec library component of Android systems, representing a critical security flaw that enables remote code execution through an integer overflow condition. This issue specifically affects Android 10 and demonstrates how audio decoding components can serve as attack vectors for sophisticated exploitation. The vulnerability manifests as an out-of-bounds write operation that occurs during the processing of Advanced Audio Coding audio files, making it particularly dangerous given the widespread use of audio playback functionality across mobile devices. The integer overflow vulnerability arises from improper handling of audio frame size calculations where the system fails to properly validate or constrain input values, allowing maliciously crafted audio data to cause memory corruption.
The technical exploitation of this vulnerability follows a well-defined attack pattern that aligns with the ATT&CK framework's execution and privilege escalation tactics. The flaw operates through a classic integer overflow scenario where an attacker crafts audio content with specifically calculated frame sizes that, when processed by the vulnerable libAACdec component, result in an overflow condition. This overflow subsequently leads to memory corruption that can be leveraged to execute arbitrary code remotely. The attack requires only user interaction through the playback of malicious audio content, making it particularly insidious as it can be triggered without requiring any special privileges or physical access to the device. The vulnerability's classification as a CWE-190 integer overflow flaw indicates the fundamental issue lies in the lack of proper input validation and overflow checking during arithmetic operations.
From an operational impact perspective, this vulnerability represents a significant threat to Android device security as it enables attackers to gain remote code execution capabilities on target devices. The absence of additional execution privileges required for exploitation means that even standard user accounts can potentially compromise device integrity. The vulnerability's remote nature allows attackers to target users through various delivery mechanisms including malicious websites, email attachments, or file sharing platforms, making it particularly dangerous in mobile environments where users frequently interact with untrusted content. The potential for widespread exploitation increases due to the ubiquity of audio playback functionality across all Android devices and the ease with which malicious audio content can be distributed.
Mitigation strategies for CVE-2019-9307 primarily focus on prompt system updates and implementation of input validation measures. Android users should immediately install security patches released by Google, which address the integer overflow condition in libAACdec through proper bounds checking and input validation. System administrators should prioritize patch deployment across all affected Android devices and consider implementing network-level controls to restrict access to potentially malicious audio content. The vulnerability's remediation aligns with standard security practices for preventing integer overflows as outlined in industry standards, emphasizing the importance of proper input validation, bounds checking, and robust error handling in multimedia processing components. Organizations should also implement monitoring solutions to detect unusual audio processing patterns that might indicate exploitation attempts, while maintaining awareness of similar vulnerabilities in other multimedia libraries and codecs.