CVE-2021-1001 in Android
Summary
by MITRE • 12/15/2021
In PVInitVideoEncoder of mp4enc_api.cpp, there is a possible out of bounds read due to a heap buffer overflow. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12Android ID: A-190435883
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-1001 represents a critical heap buffer overflow condition within the Android media processing framework, specifically within the PVInitVideoEncoder function of the mp4enc_api.cpp file. This flaw exists in the Android 12 operating system and is catalogued with the Android ID A-190435883, indicating its significance within the Android security ecosystem. The vulnerability manifests as an out-of-bounds read condition that occurs during video encoding operations, particularly when processing mp4 media files through the underlying encoding API.
The technical implementation of this vulnerability stems from inadequate bounds checking within the heap memory allocation and management processes. When the PVInitVideoEncoder function processes video encoding parameters, it fails to properly validate the size or boundaries of heap-allocated buffers, creating opportunities for memory access violations. This type of flaw falls under the Common Weakness Enumeration category CWE-125, which specifically addresses out-of-bounds read conditions. The vulnerability's exploitation pathway leverages the encoding process to trigger memory corruption that can result in information disclosure rather than direct code execution.
The operational impact of this vulnerability is significant for Android devices running version 12, as it enables local information disclosure without requiring any special privileges or user interaction for exploitation. Attackers can leverage this flaw to access sensitive data that may be stored within the heap memory regions adjacent to the improperly managed buffers. The lack of requirement for user interaction makes this vulnerability particularly concerning as it can be exploited automatically during normal media processing operations. This type of information disclosure threat aligns with ATT&CK technique T1005, which covers data from local system information, and demonstrates how media processing components can become attack vectors for information gathering.
Mitigation strategies for CVE-2021-1001 should focus on immediate patch deployment through official Android security updates, which typically include bounds checking modifications and memory management improvements. System administrators and device manufacturers should prioritize applying these updates to all affected Android 12 devices. Additional defensive measures may include implementing memory safety checks, employing address space layout randomization, and utilizing heap corruption detection mechanisms. The vulnerability highlights the importance of robust input validation in media processing libraries and underscores the need for comprehensive security testing of multimedia frameworks, particularly those handling user-provided content. Organizations should also consider network-based monitoring solutions to detect potential exploitation attempts and implement proper access controls to limit exposure of vulnerable media processing components to untrusted inputs.