CVE-2021-0412 in MT5522
Summary
by MITRE • 10/25/2021
In flv extractor, there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS05561366; Issue ID: ALPS05561366.
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Analysis
by VulDB Data Team • 10/30/2021
The vulnerability identified as CVE-2021-0412 resides within the flv extractor component of a mobile operating system, specifically affecting Android-based devices. This flaw represents a classic out-of-bounds read condition that occurs when the system fails to properly validate array indices or buffer limits during media file processing. The vulnerability is classified under CWE-129 as an insufficient bounds checking, which is a fundamental security weakness that allows unauthorized data access patterns. The issue manifests when the flv extractor attempts to parse media files without adequate validation of input parameters, creating a scenario where memory access occurs beyond the intended boundaries of allocated buffers.
The technical implementation of this vulnerability stems from the absence of proper input validation within the media processing pipeline. When the system encounters flv format files, it processes metadata and content without verifying that array indices remain within acceptable ranges. This missing bounds check creates a condition where maliciously crafted flv files could trigger memory access violations that inadvertently expose sensitive data from adjacent memory regions. The vulnerability operates at the kernel level within the media framework, leveraging the system's trust in properly formatted media files without adequate sanitization measures. According to ATT&CK framework reference T1059.007, this represents a code injection vector through legitimate system interfaces, though in this case it manifests as information disclosure rather than code execution.
The operational impact of CVE-2021-0412 extends beyond simple data exposure, as it provides attackers with potential access to sensitive information that may include system memory contents, user data, or device-specific identifiers. The vulnerability does not require any special privileges or user interaction for exploitation, making it particularly concerning for mobile environments where users frequently encounter multimedia content from untrusted sources. Local information disclosure means that an attacker with physical access to a device or the ability to deliver malicious flv files through other means could potentially extract confidential information stored in memory regions adjacent to the vulnerable code. This type of information disclosure can lead to further exploitation attempts, including credential exposure, device fingerprinting, or access to other sensitive system components that may be stored in contiguous memory locations.
Mitigation strategies for CVE-2021-0412 focus primarily on patching the affected system components and implementing additional input validation measures. The vendor has addressed this vulnerability through patch ID ALPS05561366, which includes updated bounds checking mechanisms within the flv extractor module. Security practitioners should prioritize applying this patch across all affected Android devices, particularly those running versions prior to the patched release. Additional defensive measures include implementing network-based filtering to block suspicious flv content, enabling automatic updates for media processing components, and conducting regular security assessments of media handling code within the system. Organizations should also consider implementing memory protection mechanisms such as stack canaries or address space layout randomization to mitigate potential exploitation attempts, though these measures are secondary to the primary patching requirement. The vulnerability serves as a reminder of the critical importance of bounds checking in system code, particularly within media processing frameworks where untrusted input is frequently encountered.