CVE-2016-3921 in Android
Summary
by MITRE
libsysutils/src/FrameworkListener.cpp in Framework Listener 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 2016-10-01, and 7.0 before 2016-10-01 allows attackers to gain privileges via a crafted application, aka internal bug 29831647.
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Analysis
by VulDB Data Team • 09/22/2022
The vulnerability identified as CVE-2016-3921 resides within the FrameworkListener component of Android's system utilities, specifically in the libsysutils/src/FrameworkListener.cpp file. This flaw represents a privilege escalation vulnerability that affects multiple Android versions including 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, 6.x before the 2016-10-01 security patch, and 7.0 before the same patch date. The vulnerability stems from improper input validation and privilege handling within the framework listener mechanism that manages system-level services and daemon processes.
The technical implementation of this vulnerability involves a flaw in how the FrameworkListener processes incoming commands and handles privilege transitions. When a malicious application attempts to interact with the framework listener, the system fails to properly validate the privileges associated with the incoming requests. This allows an attacker with a crafted application to exploit the system's privilege escalation mechanisms and gain elevated privileges that should normally be restricted to system-level processes. The vulnerability operates at the operating system level where standard application sandboxing mechanisms are bypassed, creating a path for unauthorized privilege elevation. This type of flaw typically falls under CWE-264, which addresses permissions, privileges, and access control issues, and aligns with ATT&CK technique T1068 for privilege escalation through exploitation of system vulnerabilities.
The operational impact of this vulnerability is significant as it enables attackers to escalate their privileges from standard application level to system-level access without requiring physical device access or additional exploitation vectors. Once successfully exploited, the malicious application could gain access to sensitive system resources, modify critical system files, access protected data, and potentially install additional malware or backdoors. The vulnerability affects the core Android framework components that manage system services, making it particularly dangerous as it could compromise the entire system integrity. Attackers could leverage this vulnerability to gain root access to devices, potentially affecting millions of Android users across multiple versions and device manufacturers.
Mitigation strategies for CVE-2016-3921 primarily involve applying the appropriate security patches released by Google and device manufacturers. Organizations should ensure that all Android devices are updated to the latest security patches, particularly those released after the 2016-10-01 date for versions 6.x and 7.0. System administrators should implement comprehensive patch management processes and regularly monitor for new security advisories. Device manufacturers should prioritize rapid deployment of security updates and maintain transparent communication about vulnerability remediation. Additional defensive measures include implementing application whitelisting policies, monitoring system logs for suspicious privilege escalation attempts, and conducting regular security assessments of Android applications to identify potential exploitation vectors. The vulnerability also highlights the importance of proper privilege separation in system design and the need for robust input validation mechanisms in all system-level components.