CVE-2019-2109 in Android
Summary
by MITRE
In MakeMPEG4VideoCodecSpecificData of AVIExtractor.cpp, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote code execution with no additional execution privileges needed. User interaction is needed for exploitation. Product: Android. Versions: Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1. Android ID: A-130651570.
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Analysis
by VulDB Data Team • 07/02/2020
The vulnerability identified as CVE-2019-2109 represents a critical out-of-bounds write flaw within the Android media processing framework, specifically in the MakeMPEG4VideoCodecSpecificData function of AVIExtractor.cpp. This issue resides in the Android operating system's multimedia handling components that process AVI video files, making it a significant security concern for devices running Android versions 7.0 through 8.1. The flaw stems from an inadequate bounds check implementation that fails to properly validate array access limits during video codec data extraction processes, creating a potential pathway for malicious code execution.
The technical implementation of this vulnerability demonstrates a classic buffer overflow condition where the application does not adequately verify the size of data being written to memory buffers. When processing AVI files containing specially crafted MPEG4 video codec specific data, the extractor function fails to validate the boundaries of its memory allocations, allowing an attacker to write data beyond the allocated buffer space. This incorrect bounds checking mechanism creates a scenario where malicious input can overwrite adjacent memory locations, potentially corrupting program execution flow or injecting executable code.
The operational impact of this vulnerability is particularly concerning as it enables remote code execution without requiring any additional privileges beyond normal user access. An attacker can exploit this flaw by crafting a malicious AVI file that, when processed by an affected Android device, triggers the vulnerable code path. The need for user interaction means that the exploit typically requires the victim to open or play the malicious media file, making it a social engineering vector that can be delivered through various attack vectors including email attachments, malicious websites, or file sharing platforms. This vulnerability affects all Android versions from 7.0 through 8.1, representing a broad attack surface across multiple Android releases.
From a cybersecurity perspective, this vulnerability aligns with CWE-129, which specifically addresses insufficient validation of length of inputs to ensure they are within acceptable bounds. The attack pattern follows typical exploit methodologies described in the MITRE ATT&CK framework under the technique of code injection and privilege escalation. The vulnerability's classification as a remote code execution flaw with no additional privileges required makes it particularly dangerous for mobile environments where users frequently interact with multimedia content from untrusted sources. The Android ID A-130651570 indicates this was properly tracked and addressed through the Android security update process, highlighting the severity of the issue as recognized by the Android security team. Organizations should implement immediate mitigation strategies including applying the relevant security patches, implementing network-based content filtering for multimedia files, and educating users about the risks of opening untrusted media files to prevent exploitation of this vulnerability.