CVE-2019-9318 in Android
Summary
by MITRE
In libhevc, there is a missing variable initialization. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-111764725
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9318 resides within the libhevc library component of Android systems, specifically affecting Android 10 releases. This issue represents a critical security flaw that stems from a missing variable initialization within the HEVC (High Efficiency Video Coding) decoding implementation. The libhevc library serves as a fundamental component for processing high-definition video content on Android devices, making this vulnerability particularly concerning given the widespread use of HEVC video formats in modern mobile applications and media playback systems.
The technical flaw manifests as a variable initialization error that occurs during the processing of HEVC video streams. When the decoder encounters malformed or specially crafted video data, the uninitialized variable can contain residual data from previous operations or memory locations, leading to information disclosure vulnerabilities. This particular weakness falls under CWE-457: Use of Uninitialized Variable, which is classified as a common software security weakness that directly impacts memory safety and data integrity. The uninitialized variable behavior creates a potential information leak where sensitive data from memory locations might be inadvertently exposed through the decoding process, potentially revealing system information, application data, or other confidential elements stored in adjacent memory regions.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables remote attackers to potentially extract sensitive information from affected Android devices without requiring any special privileges or execution rights. The vulnerability requires user interaction for exploitation, typically through the deliberate consumption of malicious video content, which could be delivered via email attachments, messaging applications, web content, or other media delivery mechanisms. This interaction requirement does not diminish the threat level significantly, as modern Android devices frequently process multimedia content automatically, making user engagement less of a barrier to successful exploitation. Attackers could craft specially formatted HEVC video files that trigger the uninitialized variable condition when processed by the libhevc library, potentially exposing memory contents that could be leveraged for further attacks.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to information gathering and privilege escalation through software exploitation. The attack chain typically begins with the delivery of malicious video content, followed by the user interaction required to initiate processing, and concludes with the information disclosure through the uninitialized variable behavior. The lack of additional execution privileges needed for exploitation makes this vulnerability particularly dangerous as it can be leveraged by attackers with minimal access requirements, potentially leading to more sophisticated attacks such as credential theft, system reconnaissance, or further exploitation of other system components. Organizations and users should consider this vulnerability as part of a broader threat landscape where multimedia content processing represents a significant attack surface that requires careful monitoring and mitigation.
The recommended mitigation strategies for CVE-2019-9318 primarily involve applying the relevant security patches provided by Google and device manufacturers, which typically include fixes to the libhevc library that properly initialize all variables before use. Additionally, organizations should implement content filtering mechanisms that can identify and block potentially malicious video content, particularly when such content originates from untrusted sources. Regular security updates and patch management processes should be prioritized to ensure that all Android devices receive the necessary fixes to address this vulnerability. Device administrators should also consider implementing network-level controls that restrict access to potentially malicious content and monitor for unusual patterns of media processing that might indicate exploitation attempts.