CVE-2019-9298 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-112892194
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9298 resides within the libAACdec library component of Android systems, representing a critical security flaw that could enable remote code execution through an integer overflow condition. This issue specifically affects Android 10 and is tracked under Android ID A-112892194, demonstrating the severity and widespread impact of such vulnerabilities within the mobile operating system ecosystem. The vulnerability stems from improper handling of integer values during audio decoding processes, creating a pathway for malicious actors to exploit the system's audio processing capabilities.
The technical flaw manifests as an integer overflow within the AAC audio decoding functionality, where the libAACdec library fails to properly validate input parameters before performing arithmetic operations. When processing specially crafted audio files, the integer overflow results in an out-of-bounds write condition that can overwrite adjacent memory locations. This memory corruption vulnerability occurs during the decoding process when the system attempts to allocate memory based on calculated values that exceed the maximum representable integer limits. The flaw specifically impacts the audio decoding pipeline where the library processes Advanced Audio Coding format files, making it particularly dangerous given the widespread use of audio content across mobile applications and media platforms.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates a potential pathway for remote code execution without requiring any additional privileges or user interaction beyond the initial exploitation vector. While the vulnerability does require user interaction to initiate the attack through the processing of malicious audio content, the fact that it can execute code remotely makes it particularly concerning for mobile environments where users frequently encounter audio content from untrusted sources. The integer overflow condition allows attackers to manipulate memory layout and potentially overwrite critical function pointers or return addresses, enabling arbitrary code execution within the context of the audio decoding process. This vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and represents a classic example of how improper input validation can lead to severe memory safety issues.
The exploitation of this vulnerability requires an attacker to craft malicious audio files that trigger the integer overflow during decoding operations, typically through manipulation of audio metadata or frame size parameters within AAC format files. The attack vector involves the user opening or playing the malicious audio content, which then triggers the vulnerable code path in libAACdec. This makes the vulnerability particularly dangerous in environments where users might encounter audio content from untrusted sources, including email attachments, messaging applications, or media streaming platforms. The lack of additional privileges required for exploitation means that successful attacks can occur without requiring elevated system permissions, making the vulnerability particularly attractive to threat actors targeting mobile devices. This aligns with ATT&CK technique T1059.007 for command and scripting interpreter, where the vulnerability could be leveraged to execute arbitrary code through the audio processing subsystem.
Mitigation strategies for CVE-2019-9298 should prioritize immediate system updates and patches provided by Google and device manufacturers, as the vulnerability affects the core audio processing capabilities of Android devices. Organizations and users should implement robust content filtering mechanisms to prevent the automatic processing of untrusted audio files, particularly those received through email, messaging, or web-based platforms. Network-level controls should be deployed to restrict access to potentially malicious audio content, while application developers should ensure proper input validation and bounds checking in their audio processing components. Device manufacturers should consider implementing additional runtime protections such as stack canaries, address space layout randomization, and control flow integrity mechanisms to reduce the effectiveness of potential exploitation attempts. Regular security audits of audio processing libraries and components should be conducted to identify similar vulnerabilities, with particular attention to integer overflow conditions and memory safety issues in multimedia processing frameworks.