CVE-2019-2148 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-113508105
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Analysis
by VulDB Data Team • 09/11/2020
The vulnerability identified as CVE-2019-2148 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 inadequate input validation mechanisms. The flaw manifests when processing audio data through the Advanced Audio Coding format implementation, where the library fails to properly verify array indices before accessing memory locations. Such missing bounds checks create a scenario where maliciously crafted audio files could trigger unauthorized memory access patterns that bypass normal execution flow controls.
The technical exploitation of this vulnerability requires user interaction, typically through the deliberate playback of specially crafted audio files that contain malformed AAC data structures. When the affected libxaac library processes these inputs without proper boundary validation, it attempts to read memory beyond the allocated buffer boundaries. This behavior results in information disclosure rather than arbitrary code execution, as the out-of-bounds read accesses memory locations containing sensitive data such as cryptographic keys, system credentials, or other confidential information. The vulnerability maps directly to CWE-125: Out-of-bounds Read, which is categorized under the broader class of memory safety issues that have been extensively documented in cybersecurity literature.
From an operational impact perspective, this vulnerability poses significant risks to Android device security and user privacy. The information disclosure aspect means that attackers could potentially extract sensitive data from memory segments that should remain protected, particularly when users interact with audio content. The requirement for user interaction limits the automated exploitation potential but does not eliminate the threat, as social engineering techniques could be employed to trick users into playing malicious audio files. This vulnerability particularly affects devices running Android 10, where the libxaac library version contains the unchecked array access pattern that enables the information leakage.
The exploitation scenario typically involves an attacker creating or distributing audio files with malformed AAC headers or payload structures that cause the libxaac library to perform invalid memory reads. When a user plays such content through standard media applications, the vulnerability triggers during audio decoding operations. The disclosed information could include system memory contents, application data, or potentially sensitive cryptographic material depending on the memory layout at the time of the read operation. This vulnerability aligns with ATT&CK technique T1059.007: Command and Scripting Interpreter: PowerShell, in that it leverages legitimate system components to achieve information disclosure objectives without requiring elevated privileges.
Mitigation strategies for CVE-2019-2148 primarily involve applying the official Android security patches released by Google, which typically include updated versions of the libxaac library with proper bounds checking mechanisms. System administrators and device manufacturers should prioritize the deployment of these updates across affected Android 10 devices to prevent exploitation. Additionally, users should exercise caution when downloading audio content from untrusted sources and avoid playing suspicious media files. Network-level defenses could include implementing content filtering mechanisms that scan audio files for known malicious patterns, though this approach has limitations given the complexity of audio format parsing. The vulnerability highlights the importance of robust input validation in multimedia libraries and underscores the need for comprehensive security testing of audio processing components in mobile operating systems.