CVE-2016-2480 in Android
Summary
by MITRE
The mm-video-v4l2 vidc component 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 2016-06-01 does not validate certain OMX parameter data structures, which allows attackers to gain privileges via a crafted application, as demonstrated by obtaining Signature or SignatureOrSystem access, aka internal bug 27532721.
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Analysis
by VulDB Data Team • 01/18/2019
The vulnerability identified as CVE-2016-2480 represents a critical privilege escalation flaw within the Android media framework, specifically targeting the mm-video-v4l2 vidc component that operates within the mediaserver process. This component serves as a crucial interface for video codec operations and is part of the broader Android multimedia subsystem that handles various media processing tasks. The vulnerability stems from inadequate input validation within the OMX parameter data structure handling mechanism, creating a pathway for malicious applications to exploit the system's trust model. The affected Android versions include 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before the 2016-06-01 security patch release, indicating this flaw persisted across multiple major Android releases and affected a significant portion of the Android ecosystem.
The technical implementation of this vulnerability involves the mediaserver process failing to properly validate OMX (OpenMAX Integration Layer) parameter structures that are passed to the vidc component during video processing operations. When a malicious application attempts to manipulate these parameter structures, the system does not perform adequate checks to ensure the data integrity and proper formatting. This lack of validation allows attackers to craft specially crafted parameter data that can trigger unintended behavior within the mediaserver process. The flaw specifically enables attackers to escalate privileges from a regular application context to a system-level access level, potentially gaining Signature or SignatureOrSystem access which provides extensive privileges including the ability to install applications with system-level permissions and access protected system resources.
The operational impact of this vulnerability is severe as it allows attackers to achieve privilege escalation without requiring physical access or root privileges. An attacker could exploit this vulnerability through a malicious application that appears legitimate to the user but contains malicious code designed to manipulate the OMX parameter structures. Once successfully exploited, the vulnerability could enable the attacker to gain access to sensitive system functions and data, potentially allowing for full system compromise. The vulnerability is particularly concerning because it operates within the core multimedia processing framework, which is frequently used by legitimate applications, making detection more difficult. This flaw aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of insufficient validation of input parameters. The vulnerability's exploitation demonstrates techniques that fall under ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," and T1548.002, which covers "Abuse of Cloud Admin Permissions" in the context of system-level access.
Mitigation strategies for CVE-2016-2480 primarily focus on applying the relevant Android security patches released by Google, which include updates to the mediaserver component and the OMX parameter validation mechanisms. Organizations and users should immediately update to Android versions that contain the security fixes, specifically Android 4.4.4, 5.0.2, 5.1.1, and the corresponding 6.x releases that were patched before the 2016-06-01 timeline. System administrators should also implement application whitelisting policies to prevent malicious applications from being installed on devices, particularly those that might attempt to access multimedia processing components. Additionally, monitoring for unusual network activity or system behavior that might indicate exploitation attempts can help detect potential attacks. The vulnerability highlights the importance of secure coding practices in system-level components and demonstrates the critical need for robust input validation, particularly in frameworks that operate with elevated privileges and handle data from untrusted sources. This vulnerability serves as a reminder of the security implications of multimedia frameworks and the necessity of comprehensive security testing for all system components that operate with system-level privileges, particularly those involved in processing user-supplied data.