CVE-2016-3920 in Android
Summary
by MITRE
id3/ID3.cpp in libstagefright in mediaserver in Android 5.0.x before 5.0.2, 5.1.x before 5.1.1, 6.x before 2016-10-01, and 7.0 before 2016-10-01 allows remote attackers to cause a denial of service (device hang or reboot) via a crafted file, aka internal bug 30744884.
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Analysis
by VulDB Data Team • 09/22/2022
The vulnerability identified as CVE-2016-3920 resides within the id3/ID3.cpp component of libstagefright, a critical media processing library embedded in Android's mediaserver service. This flaw affects multiple Android versions including 5.0.x before 5.0.2, 5.1.x before 5.1.1, 6.x before the 2016-10-01 security patch, and 7.0 before the same patch date. The vulnerability represents a serious security weakness that enables remote attackers to trigger system instability through manipulation of specially crafted media files. The affected mediaserver process handles multimedia content processing and is responsible for decoding various audio and video formats, making it a prime target for exploitation. This particular vulnerability demonstrates how media parsing components can become entry points for system compromise when proper input validation and error handling mechanisms are insufficient.
The technical implementation of this vulnerability stems from inadequate bounds checking and memory management within the ID3 metadata parsing logic. When the libstagefright library processes an ID3 tag in an audio file, it fails to properly validate the length and structure of the metadata fields, leading to potential buffer overflows or memory corruption scenarios. The flaw specifically manifests when parsing crafted ID3v2 tags that contain malformed data structures, causing the mediaserver process to enter an unstable state. This type of vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read errors. The vulnerability operates at the intersection of media processing and memory safety, where improper handling of structured data can result in arbitrary code execution or system crashes. The attack vector is particularly concerning as it requires no user interaction or privileges, making it a classic example of a remote code execution vulnerability that can be exploited through simple file delivery mechanisms.
The operational impact of CVE-2016-3920 extends beyond simple denial of service scenarios, as it can result in complete device reboots or system hangs that effectively render the affected Android device unusable. This vulnerability affects the core multimedia processing capabilities of Android devices, potentially disrupting critical services and applications that depend on media playback functionality. The mediaserver process serves as a central component for handling various media operations across the Android ecosystem, including streaming services, music players, and multimedia applications. When exploited, the vulnerability can cause cascading failures throughout the device's multimedia subsystem, affecting not only the immediate user experience but also potentially compromising the stability of other system components. The vulnerability's classification under the ATT&CK framework would fall within the privilege escalation and denial of service categories, as it can be leveraged to disrupt normal device operations and potentially create conditions for more sophisticated attacks. The affected versions span a significant portion of Android's release history, indicating the widespread nature of this vulnerability and the potential for large-scale exploitation across numerous device models and manufacturers.
Organizations and device manufacturers should prioritize immediate patching of affected Android versions to address this vulnerability, as the security implications extend far beyond simple service disruption. The remediation strategy should focus on implementing proper bounds checking and input validation within the ID3 parsing routines, ensuring that all metadata fields are thoroughly validated before processing. Security teams should also implement network-level controls to prevent the delivery of potentially malicious media files to affected devices, particularly in enterprise environments where device management policies can be enforced. The vulnerability highlights the importance of robust memory safety practices in multimedia processing libraries and the need for comprehensive testing of edge cases in metadata parsing routines. Additionally, device manufacturers should consider implementing automated vulnerability scanning and monitoring systems to detect and prevent exploitation attempts, while also ensuring that their security teams maintain awareness of similar vulnerabilities in other media processing components within the Android framework. The remediation process should include thorough regression testing to ensure that patch implementations do not introduce new stability issues or break existing functionality within the media processing pipeline.