CVE-2016-6717 in Android
Summary
by MITRE
An elevation of privilege vulnerability in Mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, 6.x before 2016-11-01, and 7.0 before 2016-11-01 could enable a local malicious application to execute arbitrary code within the context of a privileged process. This issue is rated as Moderate because it first requires exploitation of a separate vulnerability. Android ID: A-31350239.
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Analysis
by VulDB Data Team • 09/30/2022
The vulnerability identified as CVE-2016-6717 represents a critical elevation of privilege flaw within the Android mediaserver component that affected multiple versions of the Android operating system. This vulnerability exists in the mediaserver service which handles multimedia processing and playback operations, making it a prime target for attackers seeking to escalate their privileges within the Android environment. The flaw allows a local malicious application to execute arbitrary code with the elevated privileges of the mediaserver process, which typically operates with system-level permissions. This represents a significant security risk as the mediaserver process is designed to handle sensitive multimedia operations and has access to various system resources and functionalities.
The technical nature of this vulnerability stems from improper input validation within the mediaserver component's handling of multimedia files and data structures. When processing certain malformed media files or specific data sequences, the mediaserver fails to properly validate user-supplied input, creating a potential code execution pathway. This flaw falls under the CWE-121 category of stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite memory locations and potentially redirect execution flow. The vulnerability is particularly dangerous because it operates within a privileged context where the mediaserver process has extensive access to system resources, including the ability to read and write to protected memory regions and system files.
The operational impact of this vulnerability extends beyond simple privilege escalation as it creates a persistent backdoor for attackers to maintain elevated access within the Android system. Once exploited, the malicious application can leverage the elevated privileges to access sensitive system data, modify system files, install additional malware, or even disable security mechanisms. The fact that this vulnerability requires a separate initial exploitation step for the initial compromise adds complexity to the attack vector but does not diminish its severity. The mediaserver process typically runs continuously and maintains persistent access to multimedia subsystems, making it an attractive target for attackers seeking long-term system control. This vulnerability aligns with ATT&CK technique T1068 which describes the use of local privilege escalation to gain system-level access.
Mitigation strategies for CVE-2016-6717 primarily involve applying the official Android security patches released by Google as part of their regular security updates. System administrators and device manufacturers should prioritize deploying these patches across affected Android versions, particularly focusing on the specific version ranges mentioned in the vulnerability description. Additionally, implementing proper input validation and sanitization within applications that interact with multimedia processing components can help reduce the attack surface. Network segmentation and application sandboxing techniques can provide additional layers of protection by limiting the potential impact of exploitation. The vulnerability also highlights the importance of regular security audits and penetration testing of mobile applications to identify similar flaws in other system components. Organizations should also consider implementing mobile device management solutions that can automatically apply security patches and monitor for potential exploitation attempts.