CVE-2019-9347 in Android
Summary
by MITRE
In the m4v_h263 codec, there is a possible out of bounds read due to a use after free. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-109891727
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9347 resides within the m4v_h263 codec implementation in Android systems, representing a critical security flaw that manifests as an out of bounds read condition. This issue stems from a use after free error pattern where memory that has been freed is still being accessed by the codec processing routine. The m4v_h263 codec is responsible for handling multimedia content in the MPEG-4 Visual H.263 format, which is commonly used in various mobile applications and media players. When processing malformed or specially crafted video files, the codec fails to properly validate memory access patterns, leading to unauthorized data reading from memory locations that should have been released.
The technical exploitation of this vulnerability occurs through the improper handling of memory resources during video decoding operations. When the codec processes malicious input files, it attempts to access memory regions that have already been deallocated, causing the system to read data from adjacent memory locations. This use after free condition creates a scenario where sensitive information stored in previously freed memory segments can be inadvertently exposed. The vulnerability does not require any special privileges beyond normal user access, as it operates within the context of standard media processing capabilities. The lack of user interaction requirements makes this flaw particularly dangerous since it can be triggered automatically when media files are processed, such as when users open video attachments or browse media content.
From an operational impact perspective, this vulnerability presents a significant risk for local information disclosure attacks that could potentially expose sensitive data stored in memory. The compromised system could reveal confidential information including but not limited to user credentials, application data, or other sensitive memory contents that were previously stored in the freed memory regions. The vulnerability affects Android 10 systems specifically, making it relevant to a substantial portion of mobile devices that were released during the corresponding software lifecycle. The security implications extend beyond simple data exposure, as the leaked information could potentially be leveraged for further exploitation or used to gain insights into system memory structures that might aid in more sophisticated attacks.
The vulnerability aligns with CWE-416, which specifically addresses use after free conditions in software implementations, and represents a classic example of memory safety issues that plague multimedia processing components. From an attack framework perspective, this flaw would map to the privilege escalation and information gathering phases of the attack lifecycle, potentially enabling adversaries to collect sensitive data without requiring elevated privileges or user interaction. The exploitation mechanism is particularly concerning in mobile environments where users frequently encounter multimedia content from untrusted sources, making automatic triggering of this vulnerability a realistic threat scenario. Organizations should prioritize patching this vulnerability as part of their mobile security maintenance protocols, particularly given the potential for information disclosure that could impact user privacy and system integrity. The fix typically involves proper memory management practices including validating memory access patterns and ensuring that freed memory regions are not accessed during codec processing operations.