CVE-2016-5342 in Android
Summary
by MITRE
Heap-based buffer overflow in the wcnss_wlan_write function in drivers/net/wireless/wcnss/wcnss_wlan.c in the wcnss_wlan device driver for the Linux kernel 3.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, allows attackers to cause a denial of service or possibly have unspecified other impact by writing to /dev/wcnss_wlan with an unexpected amount of data.
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Analysis
by VulDB Data Team • 09/22/2022
The vulnerability identified as CVE-2016-5342 represents a critical heap-based buffer overflow within the wcnss_wlan device driver component of the Linux kernel version 3.x series. This flaw exists specifically within the wcnss_wlan_write function located in the drivers/net/wireless/wcnss/wcnss_wlan.c file, which serves as the kernel module interface for Qualcomm's wireless communication subsystem. The vulnerability affects Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and extends to various other products that utilize this kernel driver implementation. The issue manifests when the driver processes data written to the /dev/wcnss_wlan device node, where attackers can exploit the lack of proper bounds checking to overflow heap memory allocations.
The technical nature of this vulnerability stems from inadequate input validation within the wcnss_wlan_write function, which fails to properly verify the size of data being written to the device. When an attacker writes an unexpected amount of data to /dev/wcnss_wlan, the driver allocates heap memory based on initial assumptions about data size without sufficient bounds checking. This allows the attacker to write beyond the allocated buffer boundaries, potentially corrupting adjacent heap memory structures and overwriting critical metadata used by the heap allocator. The vulnerability is classified as a heap-based buffer overflow, which is categorized under CWE-121 in the Common Weakness Enumeration system, representing the classic heap overflow condition where data is written beyond the bounds of heap-allocated memory.
The operational impact of CVE-2016-5342 extends beyond simple denial of service conditions to potentially enable more severe consequences including system instability and arbitrary code execution. While the primary effect is a denial of service that can crash the wireless subsystem or cause system instability, the underlying heap corruption could theoretically be exploited to achieve privilege escalation or arbitrary code execution depending on the specific memory corruption patterns and system configuration. The vulnerability affects devices running Qualcomm MSM processors with Android operating systems, making it particularly relevant to mobile devices that rely on Qualcomm's wireless chipsets for Wi-Fi and cellular connectivity. Attackers could leverage this vulnerability to disrupt wireless communications, potentially leading to complete device compromise or service disruption in networked environments.
Mitigation strategies for CVE-2016-5342 should focus on both immediate patching and defensive system hardening measures. The most effective approach involves applying the official kernel patches released by Qualcomm and the Linux kernel community, which typically include proper bounds checking and input validation within the wcnss_wlan_write function. System administrators should also implement proper access controls on the /dev/wcnss_wlan device node to restrict write access to trusted processes only, reducing the attack surface. Additionally, monitoring for anomalous write operations to this device node can help detect potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation in kernel space drivers and aligns with ATT&CK technique T1068 which covers the exploitation of legitimate credentials and system access for privilege escalation. Organizations should also consider implementing kernel memory protection mechanisms such as stack canaries and address space layout randomization to make exploitation more difficult even if the underlying vulnerability remains unpatched.