CVE-2016-3833 in Android
Summary
by MITRE
The Shell component in Android 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-08-01 does not properly manage the MANAGE_USERS and CREATE_USERS permissions, which allows attackers to bypass intended access restrictions via a crafted application, aka internal bug 29189712.
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Analysis
by VulDB Data Team • 09/12/2022
The vulnerability described in CVE-2016-3833 represents a critical permission management flaw within the Android Shell component that affected multiple versions of the Android operating system from 2015 through early 2016. This issue resides in the core system permissions framework that governs user account management and system access controls, creating a significant security gap that could be exploited by malicious applications to gain unauthorized system privileges. The vulnerability specifically targets the MANAGE_USERS and CREATE_USERS permissions, which are fundamental system-level controls that should only be accessible to trusted system components and applications with proper authorization. The flaw allows attackers to craft malicious applications that can bypass these intended access restrictions, effectively undermining the operating system's core security model and user isolation mechanisms.
The technical implementation of this vulnerability stems from improper validation and enforcement of permission checks within the Android Shell component. When applications attempt to perform user management operations, the system should verify that the requesting application possesses the appropriate MANAGE_USERS and CREATE_USERS permissions before granting access. However, the flaw in Android versions 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-08-01 allowed malicious applications to circumvent these checks through carefully constructed permission requests or by exploiting gaps in the permission verification process. This mismanagement creates a privilege escalation vector where untrusted applications can perform actions typically restricted to system-level components, potentially enabling them to create new user accounts, modify existing user configurations, or gain elevated system privileges.
The operational impact of this vulnerability extends beyond simple permission bypass, as it fundamentally compromises the Android security model's user isolation principles. Attackers who successfully exploit this vulnerability could potentially create new user accounts with administrative privileges, modify existing user configurations, or manipulate the user management system in ways that could lead to complete system compromise. The vulnerability affects a broad range of Android devices and versions, making it particularly dangerous as it could be exploited across numerous devices in the field. This type of flaw represents a significant concern for enterprise environments where Android devices are used for business operations, as it could enable attackers to gain unauthorized access to corporate data or establish persistent access points within network environments. The vulnerability's impact aligns with CWE-284, which describes improper access control issues in software systems, and could potentially be leveraged as part of broader attack chains that follow ATT&CK techniques for privilege escalation and persistence.
Organizations and users affected by this vulnerability should prioritize immediate remediation through official Android security updates released by Google, which addressed the permission management flaw in the Shell component. System administrators should ensure all devices are updated to the latest Android versions that include the patched permission handling mechanisms, particularly focusing on the specific builds mentioned in the vulnerability description. Device manufacturers should verify that their custom Android implementations properly address this permission management gap and maintain updated security patches for their device fleets. Security monitoring should include detection of unauthorized user management activities and suspicious application behavior that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper permission management in mobile operating systems and demonstrates how flaws in core system components can create widespread security implications across the entire Android ecosystem.