CVE-2016-3823 in Android
Summary
by MITRE
The secure-session feature in the mm-video-v4l2 venc 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 2016-08-01 mishandles heap pointers, which allows attackers to gain privileges via a crafted application, aka internal bug 28815329.
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Analysis
by VulDB Data Team • 09/09/2022
The vulnerability identified as CVE-2016-3823 resides within the mm-video-v4l2 venc component of Android's mediaserver process, specifically affecting Android versions 4.x prior to 4.4.4, 5.0.x prior to 5.0.2, 5.1.x prior to 5.1.1, and 6.x prior to the 2016-08-01 security update. This flaw is categorized under CWE-125, which represents an out-of-bounds read condition that can occur when heap memory pointers are improperly managed. The secure-session feature within the mediaserver component handles video encoding operations and maintains memory management for video processing tasks. When the system processes video encoding requests through the venc component, it allocates and manages heap memory blocks to store video data and metadata. The vulnerability manifests when the system fails to properly validate or handle heap pointers during memory allocation and deallocation cycles, creating potential for memory corruption.
The technical exploitation of this vulnerability involves crafting a malicious application that can manipulate the heap pointer management within the mediaserver process. Attackers can leverage this flaw to execute arbitrary code with elevated privileges, potentially gaining root access to the Android device. The heap pointer mishandling allows for memory corruption that can be leveraged to overwrite critical memory locations, including function pointers or return addresses, enabling attackers to redirect execution flow. This privilege escalation occurs because the mediaserver process runs with elevated system privileges, and the vulnerability allows an unprivileged application to manipulate the memory space of this critical system component. The vulnerability represents a classic heap-based buffer overflow scenario where improper pointer management creates opportunities for attackers to execute code within the context of the privileged mediaserver process.
The operational impact of CVE-2016-3823 extends beyond simple privilege escalation to encompass potential system compromise and data theft. Since the mediaserver component handles multimedia processing functions, attackers who successfully exploit this vulnerability can gain access to sensitive multimedia data, potentially intercept or manipulate video streams being processed by the device. The vulnerability affects devices running vulnerable Android versions where the secure-session feature is enabled, making it particularly concerning for enterprise deployments and devices handling sensitive information. This flaw directly relates to the ATT&CK technique T1068, which involves exploiting local privileges to gain elevated access, and T1059, which covers the execution of malicious code through system processes. The vulnerability's exploitation requires minimal user interaction, as the malicious application can be installed and executed without requiring physical access or complex attack vectors.
Mitigation strategies for CVE-2016-3823 primarily involve applying the vendor-provided security patches released as part of the Android security updates. Organizations should prioritize updating devices to Android versions 4.4.4, 5.0.2, 5.1.1, or the corresponding 2016-08-01 security update, respectively. Additionally, implementing application sandboxing and restricting the execution of untrusted applications can help reduce the attack surface. System administrators should monitor for unauthorized applications that might attempt to exploit this vulnerability and consider implementing runtime application protection measures. The vulnerability highlights the importance of proper memory management practices in system-level components and underscores the need for comprehensive code reviews and security testing for privileged system processes. Organizations should also implement network monitoring to detect potential exploitation attempts and maintain up-to-date threat intelligence regarding similar heap-based vulnerabilities that may affect other system components.