CVE-2021-0411 in MT5522
Summary
by MITRE • 10/25/2021
In flv extractor, there is a possible out of bounds read due to an integer overflow. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS05561362; Issue ID: ALPS05561362.
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Analysis
by VulDB Data Team • 10/30/2021
The vulnerability identified as CVE-2021-0411 resides within the flv extractor component of a mobile operating system, specifically affecting Android devices running version 11. This flaw represents a critical security weakness that stems from improper handling of integer values during file processing operations. The vulnerability manifests as an out-of-bounds read condition that occurs when the system attempts to parse flv format files, which are commonly used for video content delivery. The integer overflow vulnerability arises from insufficient validation of file header parameters that determine buffer allocation sizes, creating a scenario where maliciously crafted flv files can trigger unexpected memory access patterns.
The technical implementation of this vulnerability follows a well-documented pattern that aligns with CWE-190, which describes integer overflow conditions that can lead to memory corruption. When the flv extractor processes a malformed file, it encounters an integer overflow during the calculation of buffer sizes required for video frame extraction. This overflow results in a situation where the system allocates insufficient memory for the intended operation, leading to memory access beyond the allocated boundaries. The flaw operates at the kernel level within the media processing framework, where the vulnerability exists in the native code responsible for handling multimedia file formats.
The operational impact of CVE-2021-0411 presents a significant risk to device security and user privacy. An attacker can exploit this vulnerability to extract sensitive information from the device's memory without requiring any form of user interaction or elevated privileges. The local information disclosure capability means that an attacker with physical access to a device or the ability to deliver a malicious flv file through other means can potentially access confidential data stored in memory regions adjacent to the vulnerable code. This includes but is not limited to user credentials, application data, system configuration details, and potentially other sensitive information that may be cached in memory during the processing of multimedia files.
The exploitation of this vulnerability occurs entirely within the context of the media processing subsystem, making it particularly concerning as it can be triggered by simply opening or processing a malicious flv file. The attack vector does not require user interaction, which means that the vulnerability can be exploited automatically when the device encounters a malicious file, whether through email attachments, web browsing, or file sharing applications. This characteristic places the vulnerability in the ATT&CK matrix under the technique T1059.007 for the execution of malicious code through media file processing, and T1005 for the collection of data from local systems.
Mitigation strategies for CVE-2021-0411 primarily focus on applying the vendor-provided patch identified by patch ID ALPS05561362. This patch addresses the integer overflow condition by implementing proper bounds checking and input validation for all buffer size calculations within the flv extractor. System administrators and device users should prioritize applying the security update as soon as it becomes available through official channels. Additionally, organizations should implement proactive monitoring of file processing activities and consider deploying network-based intrusion detection systems that can identify suspicious file transfers or processing patterns. The vulnerability serves as a reminder of the importance of robust input validation and proper integer handling in security-critical code sections, particularly in multimedia processing components that handle untrusted input from external sources.