CVE-2019-9300 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-112661610
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9300 affects the libAACdec component within Android systems, specifically present in Android 10 builds. This issue represents a critical security flaw that stems from an integer overflow condition within the Advanced Audio Coding (AAC) audio decoding library. The vulnerability manifests as a potential out of bounds write operation that can be exploited to achieve remote code execution. The integer overflow occurs during the processing of audio data, where maliciously crafted audio content can cause the decoder to miscalculate buffer boundaries, leading to memory corruption. This flaw is particularly concerning because it requires no additional privileges for exploitation, meaning that an attacker can potentially execute arbitrary code on a target device without needing elevated permissions.
The technical nature of this vulnerability aligns with CWE-190, which describes integer overflow conditions that can lead to memory corruption and arbitrary code execution. The flaw operates within the audio decoding pipeline where the AAC decoder processes incoming audio streams, and the integer overflow specifically impacts how the decoder calculates buffer sizes or array indices during audio frame processing. The vulnerability requires user interaction for exploitation, typically through the playback of maliciously crafted audio files or streams, making it particularly dangerous in scenarios where users might encounter such content during normal device usage. This interaction requirement places the vulnerability in the ATT&CK framework under the T1203 technique for legitimate system interactions, where adversaries leverage normal user behaviors to deliver malicious payloads.
The operational impact of CVE-2019-9300 extends beyond simple remote code execution as it represents a complete compromise of the affected device's security posture. Once exploited, the vulnerability allows attackers to gain full control over the target Android device, potentially enabling data exfiltration, persistent backdoor installation, or further lateral movement within network environments. The fact that this vulnerability exists in the core audio decoding libraries means that it can be triggered through various legitimate audio playback scenarios, including streaming services, downloaded media files, or even Bluetooth audio connections. The vulnerability's presence in Android 10 specifically indicates that all devices running this version are potentially at risk, making it a widespread concern for device manufacturers and security professionals. The exploitation process likely involves crafting audio content that causes the decoder to overflow integer values, resulting in memory corruption that can be leveraged to overwrite critical program memory locations and redirect execution flow. Mitigation efforts should focus on immediate patch deployment and potentially implementing runtime protections or sandboxing mechanisms to limit the impact of such vulnerabilities in the event of exploitation attempts.
The vulnerability demonstrates the ongoing challenges in audio codec security, where complex decoding algorithms can introduce subtle flaws that have severe consequences for system security. The integer overflow in libAACdec represents a classic example of how mathematical operations in security-critical components can lead to memory corruption vulnerabilities. This flaw underscores the importance of proper input validation and boundary checking in multimedia processing libraries, particularly those handling user-controllable data streams. The vulnerability's classification as requiring user interaction suggests that it may be difficult to exploit at scale without social engineering components, but the potential for automated exploitation through certain media delivery mechanisms remains a concern for security practitioners. Device manufacturers and security teams must prioritize immediate patching of affected Android 10 devices and consider implementing additional security controls to protect against similar vulnerabilities in other multimedia components. The vulnerability also highlights the need for comprehensive security testing of multimedia libraries, particularly those that handle complex data formats and require real-time processing capabilities that may introduce additional attack surface areas.