CVE-2016-5347 in Android
Summary
by MITRE
In all Qualcomm products with Android releases from CAF using the Linux kernel, kernel stack data can be leaked to userspace by an audio driver.
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Analysis
by VulDB Data Team • 12/15/2022
The vulnerability identified as CVE-2016-5347 represents a critical information disclosure flaw affecting Qualcomm-based Android devices that utilize the Linux kernel. This issue resides within the audio driver component of the kernel, specifically within the Qualcomm Android Flashing (CAF) framework. The vulnerability allows unauthorized access to kernel stack memory contents, which can contain sensitive data such as cryptographic keys, passwords, or other confidential information that should remain isolated within kernel space. The flaw impacts all Qualcomm products running Android versions that incorporate the Linux kernel, making it particularly widespread across mobile devices and embedded systems that depend on Qualcomm's hardware platforms.
The technical mechanism behind this vulnerability involves improper memory management within the audio driver's kernel module. When userspace applications interact with the audio subsystem through ioctl calls or other kernel interfaces, the driver fails to properly validate or sanitize memory access patterns. This allows malicious or exploited applications to craft specific requests that cause the kernel to inadvertently expose stack data to userspace processes. The vulnerability is classified under CWE-200 as "Information Exposure" and specifically relates to improper information handling within kernel modules. The flaw essentially creates a path where kernel memory addresses and their contents become accessible through legitimate kernel interfaces, violating fundamental security principles of kernel isolation and memory protection.
The operational impact of CVE-2016-5347 extends beyond simple information disclosure, as the leaked kernel stack data can contain sensitive cryptographic material, session tokens, or other confidential information that could be exploited by attackers. This vulnerability enables techniques such as kernel address space layout randomization (ASLR) bypass, where attackers can extract kernel memory addresses and use this information to plan more sophisticated attacks. The exposure of kernel stack contents provides attackers with valuable information about kernel memory layout, which can be leveraged for privilege escalation or to develop more targeted exploits. From an attack framework perspective, this vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, and T1068 for exploit for privilege escalation, as it enables attackers to gain deeper insights into system memory structures and potentially escalate their privileges.
Mitigation strategies for CVE-2016-5347 focus on both immediate patching and defensive measures. Qualcomm released kernel updates addressing this vulnerability, which should be deployed immediately across affected devices. System administrators should also implement runtime monitoring to detect suspicious memory access patterns and ensure proper kernel module permissions are enforced. The vulnerability highlights the importance of kernel memory protection mechanisms and proper input validation within driver code. Organizations should consider implementing kernel hardening techniques such as stack canaries, kernel address space layout randomization, and strict kernel module loading policies. Additionally, regular security audits of kernel drivers and memory management functions should be conducted to identify similar vulnerabilities. The remediation process requires careful consideration of device compatibility and potential regression issues, as kernel patches may affect audio functionality or system stability.