CVE-2019-2157 in Android
Summary
by MITRE
In libxaac, there is a possible out of bounds read due to a missing bounds check. This could lead to information disclosure with no additional execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-112611363
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Analysis
by VulDB Data Team • 09/11/2020
The vulnerability identified as CVE-2019-2157 resides within the libxaac library component of Android systems, specifically affecting Android 10 deployments. This issue represents a classic out-of-bounds read condition that stems from insufficient input validation mechanisms within the audio decoding framework. The flaw manifests when processing audio data that has been improperly validated, creating a scenario where the application attempts to access memory locations beyond the allocated buffer boundaries. This particular vulnerability falls under the CWE-129 category of Improper Input Validation, which encompasses issues related to inadequate bounds checking in array or buffer operations. The security implications are particularly concerning as this vulnerability can potentially expose sensitive information stored in memory locations that should remain protected from unauthorized access.
The technical execution of this vulnerability requires user interaction, meaning an attacker must convince a victim to perform a specific action that triggers the malformed audio processing. This typically occurs when a user encounters specially crafted audio content that contains maliciously formatted data within the AAC audio stream. The missing bounds check in libxaac means that when the audio decoding process attempts to parse the malformed data, it reads beyond the intended memory allocation, potentially retrieving data from adjacent memory locations. These locations could contain sensitive information such as cryptographic keys, user credentials, or other confidential data that was stored in memory. The Android security model recognizes this as a medium severity issue that can be exploited through a privilege escalation path requiring no additional execution privileges beyond normal user access.
The operational impact of CVE-2019-2157 extends beyond simple information disclosure, as it represents a potential vector for more sophisticated attacks within the Android ecosystem. When an attacker successfully exploits this vulnerability, they gain access to memory contents that may include session tokens, application data, or system information that could be leveraged for further exploitation. The Android security architecture, particularly the sandboxing mechanisms that separate applications and protect user data, could be compromised through this information disclosure. This vulnerability is particularly concerning in the context of the ATT&CK framework where it aligns with techniques related to information gathering and privilege escalation. The Android ID A-112611363 indicates that this issue was properly tracked within Google's internal vulnerability management system, demonstrating the recognition of the severity and potential impact on user privacy and system integrity. Organizations should implement immediate mitigations including applying the latest security patches and monitoring for potential exploitation attempts.
Mitigation strategies for CVE-2019-2157 should focus on both immediate remediation and long-term security hardening measures. The primary recommendation involves deploying the Android security patches released by Google that address the bounds checking issue within libxaac. Additionally, system administrators should consider implementing network-level controls to filter potentially malicious audio content and monitor for unusual patterns in audio processing activities. The vulnerability highlights the importance of proper input validation in multimedia processing libraries and reinforces the need for comprehensive security testing of third-party components. Organizations should also review their application security practices to ensure that similar bounds checking issues are not present in other components of their systems. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues before they can be exploited by malicious actors. The vulnerability serves as a reminder of the critical importance of robust memory management practices in security-sensitive applications.