CVE-2019-9261 in Android
Summary
by MITRE
In libxaac there is a possible out of bounds read due to 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-116774214
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9261 affects the libxaac library component within Android systems, specifically manifesting in Android 10 operating on devices with Android ID A-116774214. This issue represents a classic out-of-bounds read condition that stems from inadequate input validation mechanisms. The flaw resides in the audio processing subsystem where the libxaac library handles advanced audio coding format files, particularly when processing malformed or specially crafted audio data streams.
The technical implementation of this vulnerability demonstrates a missing bounds check within the audio decoding logic that processes AAC (Advanced Audio Coding) format files. When the library attempts to read audio data beyond the allocated buffer boundaries, it accesses memory locations that may contain sensitive information from other processes or system components. This condition occurs during the parsing of audio metadata or frame data where the library fails to validate the size parameters before attempting memory access operations. The absence of proper validation allows an attacker to craft malicious audio files that trigger the out-of-bounds read scenario, potentially exposing confidential data stored in adjacent memory regions.
The operational impact of this vulnerability extends beyond simple information disclosure as it represents a significant security risk within the Android multimedia framework. Attackers can exploit this weakness through user interaction by simply playing or processing a specially crafted audio file, requiring no elevated privileges or root access. The vulnerability's exploitation path aligns with the ATT&CK technique T1059.007 for execution through audio processing and T1068 for local privilege escalation through memory corruption. The security implications are particularly concerning given that audio processing occurs frequently in mobile environments, making the attack surface relatively large and accessible.
From a security standards perspective, this vulnerability maps directly to CWE-129 which describes "Improper Validation of Array Index" and CWE-131 which covers "Incorrect Calculation of Buffer Size." The flaw represents a classic buffer over-read condition that can lead to information disclosure and potentially more severe consequences if combined with other vulnerabilities. The Android security model's reliance on proper input validation makes this issue particularly dangerous as it bypasses several layers of security protection that typically guard against such memory access violations. The vulnerability demonstrates poor defensive programming practices where boundary checks are omitted during audio data processing operations, creating an exploitable condition that can reveal sensitive information from system memory.
Mitigation strategies for CVE-2019-9261 should focus on implementing comprehensive input validation and boundary checking within the libxaac library. Android device manufacturers and security teams should prioritize immediate patch deployment through security updates that address the missing bounds check in audio processing components. The solution involves adding proper validation routines that verify buffer sizes before memory access operations, ensuring that all audio data streams are properly sanitized before processing. Additionally, implementing memory protection mechanisms such as stack canaries and address space layout randomization can provide additional defense-in-depth measures. Regular security audits of multimedia processing libraries should be conducted to identify similar boundary condition vulnerabilities, with particular attention to components handling user-supplied data in mobile operating systems. The vulnerability underscores the importance of robust input validation in multimedia frameworks and the critical need for comprehensive testing of audio processing components against malformed input scenarios.