CVE-2016-3819 in Android
Summary
by MITRE
Integer overflow in codecs/on2/h264dec/source/h264bsd_dpb.c in libstagefright in mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-08-01 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted media file, aka internal bug 28533562.
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Analysis
by VulDB Data Team • 09/09/2022
The vulnerability identified as CVE-2016-3819 represents a critical integer overflow flaw within the Android media processing framework that affects multiple versions of the Android operating system. This vulnerability resides in the libstagefright library's H.264 video decoding component, specifically in the h264bsd_dpb.c file which manages decoded picture buffer operations. The flaw occurs during the processing of H.264 video streams where the system fails to properly validate integer values during buffer allocation calculations, creating a condition where maliciously crafted media files can trigger unexpected behavior in the underlying memory management system.
The technical exploitation of this vulnerability stems from the improper handling of integer arithmetic within the video decoding pipeline. When processing maliciously constructed H.264 streams, the system performs calculations that exceed the maximum representable value for the integer data type, causing the value to wrap around to a much smaller number. This overflow condition directly impacts the memory allocation routines that determine how much space to reserve for decoded video frames in the decoded picture buffer. The resulting memory corruption can lead to arbitrary code execution when the corrupted memory is subsequently accessed during normal video playback operations, or cause a denial of service through memory corruption that crashes the media server process.
This vulnerability directly maps to CWE-190, Integer Overflow or Wraparound, which is a well-documented weakness in software systems where integer arithmetic operations produce values that exceed the maximum capacity of the data type being used. The attack surface is particularly concerning as it operates at the system level within the mediaserver process that handles all multimedia content processing across the Android platform. The vulnerability affects Android versions from 4.x through 6.x, representing a significant portion of the mobile operating system ecosystem during that timeframe. The remote nature of the attack means that an attacker can deliver a malicious media file through various channels including email attachments, web downloads, or multimedia content shared via social media platforms without requiring any special privileges or user interaction beyond opening the media file.
The operational impact of this vulnerability extends beyond simple exploitation as it represents a fundamental security weakness in the Android media processing stack that could be leveraged for persistent attacks. When exploited successfully, the vulnerability allows attackers to gain unauthorized code execution privileges within the context of the mediaserver process, which typically runs with elevated system privileges. This creates opportunities for attackers to escalate their privileges, access sensitive user data, or establish persistent backdoors on affected devices. The vulnerability also impacts device availability through denial of service conditions that can crash the media server and potentially cause the entire device to become unresponsive during media playback operations. Organizations and users affected by this vulnerability should consider implementing immediate mitigation strategies including applying security patches, disabling media processing capabilities for untrusted content, and monitoring for suspicious network activity that might indicate exploitation attempts.
The ATT&CK framework categorizes this vulnerability under the T1059.007 technique for command and script interpreter, as exploitation requires the execution of malicious code through compromised media processing functionality. Additionally, this vulnerability aligns with T1499.004 for endpoint denial of service, as the memory corruption can be used to crash system services. The vulnerability's classification as a remote code execution flaw places it within the high-risk category of mobile security threats, particularly concerning Android devices that process multimedia content from untrusted sources. Security professionals should note that this vulnerability demonstrates the critical importance of proper integer validation in systems handling multimedia content, as similar flaws have been identified in other media processing libraries and frameworks across various platforms.