CVE-2019-2151 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-117495174
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Analysis
by VulDB Data Team • 09/11/2020
The vulnerability identified as CVE-2019-2151 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 (AAC) decoding functionality, where the system fails to properly verify array indices before accessing memory locations. Such missing bounds checks create opportunities for unauthorized data access patterns that can reveal sensitive information stored in adjacent memory regions. The vulnerability requires user interaction to exploit effectively, typically through the deliberate manipulation of malformed audio files or media content that triggers the affected decoding path. This characteristic places the risk in the context of social engineering or targeted attacks where adversaries can influence system behavior through crafted media inputs. The potential information disclosure impact arises from the ability to read memory contents that should remain protected, potentially exposing system internals, user data, or cryptographic keys. This vulnerability aligns with CWE-129, which specifically addresses insufficient bounds checking in array access operations, and represents a significant concern for mobile security environments where multimedia processing is prevalent. The Android security advisory A-117495174 documents this weakness as part of the broader Android 10 security patch cycle, emphasizing the need for proper input validation in multimedia libraries.
The technical exploitation of CVE-2019-2151 occurs when the libxaac library processes audio content that contains malformed data structures designed to trigger the missing bounds check. During normal operation, the AAC decoder expects well-formed input data with predictable memory access patterns, but the absence of proper validation allows attackers to craft inputs that cause the decoder to read beyond allocated memory boundaries. This read operation can potentially access sensitive information from adjacent memory locations, including but not limited to authentication tokens, session data, or other confidential system information. The vulnerability operates at the application layer where audio processing occurs, making it particularly dangerous in mobile environments where users frequently interact with multimedia content. The requirement for user interaction means that exploitation typically occurs through user engagement with malicious media files, such as specially crafted audio files that appear legitimate but contain malicious payload structures designed to trigger the out-of-bounds read. This attack vector aligns with ATT&CK technique T1203, which involves the use of malicious files to execute code or gain information, and represents a common pattern in mobile security exploitation. The absence of additional execution privileges required for exploitation makes this vulnerability particularly concerning as it can be leveraged without requiring escalated system access or root privileges.
The operational impact of CVE-2019-2151 extends beyond simple information disclosure to potentially compromise user privacy and system integrity within Android environments. When exploited, the vulnerability can lead to exposure of sensitive user data, including personal information stored in memory, application state data, or communication session details that could be valuable to adversaries. The vulnerability affects the core multimedia processing capabilities of Android devices, potentially disrupting normal user operations while simultaneously providing attackers with access to confidential information. The risk is compounded by the fact that this vulnerability exists in widely deployed components of the Android operating system, meaning that a significant portion of Android 10 devices could be potentially affected. Organizations and users should consider this vulnerability in their risk assessment frameworks, particularly in environments where mobile device security is paramount. The information disclosure aspect of this vulnerability can enable further attacks by providing attackers with insights into system behavior, memory layouts, or application states that could facilitate more sophisticated exploitation techniques. The presence of this flaw in the audio processing pipeline means that even benign-looking media content could serve as a vector for information extraction, making it particularly challenging to defend against. Security practitioners should prioritize this vulnerability in their patch management schedules and consider implementing additional monitoring for anomalous audio processing behaviors that might indicate exploitation attempts. The vulnerability's classification as a memory safety issue places it within the scope of common attack patterns documented in various security frameworks, including those addressing mobile device security and application sandboxing mechanisms.