CVE-2016-3837 in Android
Summary
by MITRE
service/jni/com_android_server_wifi_WifiNative.cpp in Wi-Fi in Android 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-08-01 allows attackers to obtain sensitive information via a crafted application that provides a MAC address with too few characters, aka internal bug 28164077.
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Analysis
by VulDB Data Team • 09/12/2022
The vulnerability identified as CVE-2016-3837 resides within the Android Wi-Fi subsystem, specifically in the service/jni/com_android_server_wifi_WifiNative.cpp component. This flaw affects Android versions 5.0.x prior to 5.0.2, 5.1.x prior to 5.1.1, and all 6.x versions before the 2016-08-01 security update. The vulnerability stems from inadequate input validation mechanisms within the Wi-Fi native service that handles MAC address processing. Attackers can exploit this weakness by crafting a malicious application that submits a MAC address containing insufficient characters, thereby triggering unintended behavior in the underlying Wi-Fi service implementation.
The technical exploitation of this vulnerability involves a buffer over-read or improper memory handling scenario where the system attempts to process a MAC address that does not meet the expected format requirements. When a crafted application provides a MAC address with too few characters, the Wi-Fi native service fails to properly validate the input length before attempting to parse or process the address. This inadequate validation creates a path where sensitive information stored in memory adjacent to the MAC address buffer can be inadvertently exposed to the malicious application. The flaw operates at the JNI (Java Native Interface) layer, bridging the gap between Android's Java-based application framework and the underlying C/C++ Wi-Fi native service implementation.
The operational impact of CVE-2016-3837 extends beyond simple information disclosure, as it represents a potential vector for more sophisticated attacks within the Android security model. An attacker with a crafted application could potentially extract sensitive data from the Wi-Fi service memory space, including but not limited to authentication tokens, network configuration details, or other system information that could aid in further exploitation. This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and demonstrates how improper input validation in native code can lead to information disclosure. The vulnerability also maps to ATT&CK technique T1059.007 for execution through native APIs and T1046 for network service enumeration, as it could enable attackers to gather information about network configurations and Wi-Fi service internals.
Mitigation strategies for this vulnerability require immediate patch application to affected Android versions, as the issue was resolved through proper input validation mechanisms in the Wi-Fi native service code. Organizations should ensure all Android devices running affected versions receive the appropriate security updates, particularly those released before 2016-08-01. Additionally, network administrators should implement monitoring for suspicious Wi-Fi activity patterns that might indicate exploitation attempts. The fix typically involves implementing robust validation checks for MAC address format and length before processing, ensuring that any input fails validation if it does not meet the expected IEEE 802.11 MAC address specifications. Device manufacturers and carriers should prioritize rolling out these security patches to prevent exploitation and maintain the integrity of wireless network communications within the Android ecosystem.