CVE-2016-5346 in Pixel
Summary
by MITRE
An Information Disclosure vulnerability exists in the Google Pixel/Pixel SL Qualcomm Avtimer Driver due to a NULL pointer dereference when processing an accept system call by the user process on AF_MSM_IPC sockets, which could let a local malicious user obtain sensitive information (Android Bug ID A-32551280).
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Analysis
by VulDB Data Team • 04/14/2023
The vulnerability described in CVE-2016-5346 represents a critical information disclosure flaw within the Google Pixel and Pixel SL devices, specifically within the Qualcomm Avtimer driver component. This issue manifests through a NULL pointer dereference condition that occurs during the processing of accept system calls on AF_MSM_IPC sockets, creating a pathway for unauthorized information retrieval. The vulnerability is particularly concerning as it affects the underlying Android operating system kernel components and operates at a level that could be exploited by local malicious users without requiring elevated privileges.
The technical implementation of this flaw involves the Qualcomm Avtimer driver's handling of socket operations within the Android framework. When a user process attempts to accept connections on AF_MSM_IPC sockets, which are used for communication between different kernel modules and user space applications, the driver fails to properly validate pointer references. This NULL pointer dereference creates an opportunity for information leakage, as the system's response to this error condition inadvertently exposes kernel memory contents to the calling process. The vulnerability is classified under CWE-476 as a NULL pointer dereference, which represents a common software flaw that can lead to information disclosure when the system does not properly handle error conditions.
From an operational perspective, this vulnerability presents significant risks to device security and data integrity. Local malicious users who can execute code on the device can leverage this flaw to extract sensitive information from kernel memory, potentially including cryptographic keys, user credentials, or other confidential data. The attack vector is particularly dangerous because it requires only local access to the device, making it accessible through various attack scenarios including compromised applications or malicious user accounts. The Android Bug ID A-32551280 indicates that this issue was tracked within Google's internal vulnerability management system, highlighting the severity of the flaw and its potential impact on mobile device security.
The security implications extend beyond simple information disclosure, as the leaked kernel memory could contain sensitive data structures that might aid in further exploitation attempts. Attackers could potentially use the disclosed information to craft more sophisticated attacks, including privilege escalation or bypassing security mechanisms. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, and T1068 for exploit for privilege escalation, as it provides a potential foothold for more advanced attacks. This flaw demonstrates the critical importance of proper input validation and error handling in kernel-level drivers, particularly those managing inter-process communication channels that are fundamental to system operation.
Mitigation strategies for this vulnerability should focus on both immediate patching and defensive measures. Device manufacturers and security teams should prioritize applying the relevant security updates that address the NULL pointer dereference in the Qualcomm Avtimer driver. Additionally, system administrators should implement monitoring for unusual socket activity patterns that might indicate exploitation attempts. The vulnerability highlights the need for comprehensive kernel security testing, including formal verification of error handling paths and robust pointer validation mechanisms. Organizations should also consider implementing application whitelisting and privilege separation to limit the potential impact of local exploits, as well as regular security audits of kernel components to identify similar vulnerabilities that might exist in other driver modules.