CVE-2016-3742 in Android
Summary
by MITRE
decoder/ih264d_process_intra_mb.c in mediaserver in Android 6.x before 2016-07-01 mishandles intra mode, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted media file, aka internal bug 28165659.
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Analysis
by VulDB Data Team • 02/21/2019
The vulnerability described in CVE-2016-3742 resides within the Android mediaserver component, specifically in the decoder/ih264d_process_intra_mb.c file that handles H.264 video decoding operations. This flaw affects Android 6.x versions prior to the 2016-07-01 security update, representing a critical security weakness that could be exploited by remote attackers through maliciously crafted media files. The vulnerability stems from improper handling of intra mode processing during video decoding, creating a pathway for attackers to manipulate memory structures and potentially execute arbitrary code on affected devices.
The technical implementation of this vulnerability involves a memory corruption issue that occurs when processing intra macroblocks within H.264 video streams. During normal video decoding operations, the mediaserver component processes intra macroblocks using specific prediction modes to reconstruct video frames. However, the flaw in the ih264d_process_intra_mb.c file fails to properly validate or handle certain intra mode parameters, leading to buffer overflows or memory corruption when processing malformed input data. This type of vulnerability falls under CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation in multimedia processing components. The vulnerability is particularly dangerous because it operates within the mediaserver process, which runs with elevated privileges and has access to core system resources.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to include potential remote code execution capabilities. Attackers can craft specially designed media files that, when processed by the vulnerable Android mediaserver, trigger memory corruption conditions that may allow arbitrary code execution. This represents a significant threat to mobile device security since media files are commonly shared through various channels including email attachments, messaging applications, social media platforms, and web downloads. The vulnerability's exploitation potential aligns with ATT&CK technique T1059.007, which covers command and scripting interpreter usage, as successful exploitation could enable attackers to execute malicious code on target devices. Additionally, the vulnerability demonstrates characteristics of T1203, which involves legitimate programs being used for code execution, as the legitimate mediaserver process becomes the vector for malicious activity.
Mitigation strategies for CVE-2016-3742 primarily focus on applying the security patch released by Google in their July 2016 security bulletin, which specifically addresses this memory corruption issue in the H.264 decoder. Device manufacturers should prioritize rolling out the patched Android 6.0.1 update to affected devices, as this vulnerability affects all Android 6.x devices that have not received the relevant security update. Network administrators should consider implementing media file filtering policies to prevent the distribution of potentially malicious media content, particularly in enterprise environments where device security is paramount. The vulnerability also underscores the importance of input validation and bounds checking in multimedia processing libraries, as similar issues may exist in other video decoding components. Organizations should conduct regular security assessments of their mobile device management systems to identify and remediate similar vulnerabilities in other multimedia processing components that may be susceptible to similar memory corruption attacks.