CVE-2016-3874 in Android
Summary
by MITRE
CORE/HDD/src/wlan_hdd_wext.c in the Qualcomm Wi-Fi driver in Android before 2016-09-05 on Nexus 5X devices does not properly validate the arguments array, which allows attackers to gain privileges via a crafted application that sends a WE_UNIT_TEST_CMD command, aka Android internal bug 29944562 and Qualcomm internal bug CR997797.
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Analysis
by VulDB Data Team • 09/15/2022
The vulnerability identified as CVE-2016-3874 represents a critical privilege escalation flaw within the Qualcomm Wi-Fi driver component of Android operating systems. This issue specifically affects Nexus 5X devices running Android versions prior to the 2016-09-05 security update, creating a significant attack surface that adversaries could exploit to elevate their privileges from standard application level access to system-level control. The vulnerability resides in the wlan_hdd_wext.c source file within the CORE/HDD/src directory of the Qualcomm Wi-Fi driver implementation, making it a fundamental component of the wireless networking stack that handles ioctl commands for wireless extensions.
The technical flaw stems from inadequate validation of argument arrays within the WE_UNIT_TEST_CMD command handler, which is part of the wireless extensions interface used by the Linux kernel to communicate with wireless drivers. When a malicious application sends a crafted WE_UNIT_TEST_CMD command with malformed arguments, the driver fails to properly validate these inputs before processing them, creating a buffer overflow condition or arbitrary code execution opportunity. This validation failure aligns with CWE-121, which describes buffer overflow conditions due to insufficient input validation, and represents a classic example of improper input validation that allows attackers to manipulate the driver's behavior. The vulnerability specifically targets the wireless driver's ioctl handling mechanism, where the WE_UNIT_TEST_CMD command is intended for internal testing purposes but can be exploited due to the lack of proper argument validation.
The operational impact of this vulnerability is severe as it enables attackers to achieve privilege escalation from application level to system level execution, potentially allowing full control over the device. Once exploited, an attacker could gain access to sensitive device functions including network monitoring, data exfiltration, and modification of system configurations. The attack vector is particularly concerning because it requires only a crafted application to be installed and executed, making it accessible to adversaries who might distribute malicious apps through various channels. The vulnerability affects devices running Android versions before the September 2016 security patch, leaving a substantial number of devices exposed to potential exploitation. According to ATT&CK framework, this vulnerability maps to privilege escalation techniques under the T1068 category, specifically targeting the exploitation of kernel-level vulnerabilities to gain elevated privileges.
Mitigation strategies for CVE-2016-3874 primarily focus on applying the relevant security patches released by Google and Qualcomm, which include updated Wi-Fi driver components that properly validate command arguments. Device administrators should ensure immediate deployment of the Android security update released on September 5, 2016, which addresses this specific vulnerability. Additionally, security measures should include monitoring for unauthorized applications that might attempt to exploit this flaw, implementing application whitelisting policies, and conducting regular vulnerability assessments of wireless networking components. The fix implemented by Qualcomm involves strengthening input validation in the wireless driver's command processing logic, ensuring that all arguments to the WE_UNIT_TEST_CMD are properly validated before any processing occurs. Organizations should also consider network-level monitoring to detect unusual wireless activity patterns that might indicate exploitation attempts, as the vulnerability could potentially be used for persistent access to compromised devices.