CVE-2020-0491 in Android
Summary
by MITRE • 12/15/2020
In readBlock of MatroskaExtractor.cpp, there is a possible denial of service due to resource exhaustion. This could lead to remote denial of service with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-156819528
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Analysis
by VulDB Data Team • 12/18/2020
The vulnerability identified as CVE-2020-0491 represents a critical resource exhaustion flaw within the Matroska media file parser component of Android's media framework. This issue manifests in the readBlock function of MatroskaExtractor.cpp, where improper handling of malformed media files can lead to excessive memory consumption and system resource depletion. The vulnerability specifically affects Android 11 systems and is tracked under Android ID A-156819528, demonstrating the potential for widespread impact across the Android ecosystem where media processing is prevalent.
The technical flaw stems from inadequate input validation and memory management within the Matroska container format parser. When processing specially crafted malicious Matroska files, the readBlock function fails to properly constrain memory allocation based on input parameters, leading to unbounded resource consumption. This vulnerability operates at the media processing layer where Android applications and system services parse multimedia content, making it particularly dangerous as it can be triggered through various media consumption pathways including email attachments, web downloads, or media file sharing applications. The flaw aligns with CWE-400, which categorizes resource exhaustion vulnerabilities, and specifically demonstrates characteristics of CWE-770 where insufficient restrictions on resource allocation lead to denial of service conditions.
The operational impact of this vulnerability extends beyond simple system instability to potentially enable remote exploitation without requiring elevated privileges or user interaction beyond the initial media file consumption. An attacker could craft malicious Matroska files that, when processed by an Android device, would trigger the resource exhaustion condition and result in system denial of service. This makes the vulnerability particularly concerning for mobile environments where devices are constantly processing media content and where users may inadvertently encounter malicious files through various digital channels. The vulnerability's classification under the Android security framework indicates its severity and the potential for widespread compromise across affected devices.
Mitigation strategies for CVE-2020-0491 should focus on implementing robust input validation and memory allocation limits within the media processing framework. System administrators and developers should ensure that all media file parsers enforce strict bounds checking and implement proper resource management techniques to prevent unbounded memory allocation. The Android security team addressed this vulnerability through system updates that enhanced the Matroska parser's resource management capabilities and introduced additional validation checks to prevent malformed input from causing resource exhaustion. Organizations should prioritize applying the latest Android security patches and consider implementing additional media file sanitization measures at network boundaries to prevent exploitation attempts. This vulnerability also highlights the importance of following ATT&CK framework principles for mobile security, particularly in the context of process injection and resource exhaustion attack vectors that target media processing components.