CVE-2016-3933 in Android
Summary
by MITRE
mediaserver in Android before 2016-10-05 on Nexus 9 and Pixel C devices allows attackers to gain privileges via a crafted application, aka internal bug 29421408.
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Analysis
by VulDB Data Team • 05/01/2019
The vulnerability identified as CVE-2016-3933 represents a critical privilege escalation flaw within the mediaserver component of Android operating systems. This issue specifically affected Nexus 9 and Pixel C devices released before the security patch date of October 5, 2016, creating a significant attack surface for malicious actors seeking to elevate their privileges within the Android ecosystem. The mediaserver process serves as a critical system component responsible for handling multimedia operations and file processing, making it an attractive target for attackers looking to gain elevated system access.
The technical flaw stems from insufficient input validation and improper privilege handling within the mediaserver daemon. Attackers could craft malicious applications that exploit memory corruption vulnerabilities or improper access controls to manipulate the mediaserver process. This weakness allowed unauthorized code execution with elevated privileges, potentially enabling full system compromise. The vulnerability specifically leveraged the trust relationship between the mediaserver and underlying system components, bypassing normal security boundaries that should prevent unauthorized privilege escalation.
The operational impact of this vulnerability extends beyond simple privilege elevation, as it provides attackers with complete control over affected devices. Once exploited, compromised systems could be used for data exfiltration, persistent backdoor installation, or as launching points for further attacks within network environments. The affected Nexus 9 and Pixel C devices represent a significant portion of Android users during that time period, making this vulnerability particularly dangerous from a threat intelligence perspective. The vulnerability's exploitation typically requires social engineering or delivery of malicious applications, but once executed, it creates a persistent threat vector that can be difficult to detect and remediate.
Mitigation strategies for CVE-2016-3933 primarily focus on timely patch deployment and system hardening measures. Organizations should prioritize updating all affected Android devices to the latest security patches released by Google, particularly addressing the October 2016 security update. System administrators should implement mobile device management solutions to ensure comprehensive patch coverage across all enterprise devices. Additional defensive measures include network monitoring for suspicious mediaserver activity, application whitelisting to prevent execution of untrusted code, and regular security assessments of mobile device configurations. From a cybersecurity framework perspective, this vulnerability aligns with CWE-20 (Improper Input Validation) and represents a classic example of privilege escalation techniques documented in the MITRE ATT&CK framework under the Privilege Escalation tactic. The vulnerability also demonstrates the importance of secure coding practices and proper privilege separation in system components, particularly those handling multimedia processing tasks that interface with system-level resources.