CVE-2017-14900 in Android
Summary
by MITRE
In Android for MSM, Firefox OS for MSM, QRD Android, with all Android releases from CAF using the Linux kernel, while processing the QCA_NL80211_VENDOR_SUBCMD_GET_CHAIN_RSSI vendor command, in which attribute QCA_WLAN_VENDOR_ATTR_MAC_ADDR contains fewer than 6 bytes, a buffer overrun occurs.
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Analysis
by VulDB Data Team • 12/21/2019
This vulnerability exists within the Linux kernel implementations used in various Android and Firefox OS devices, specifically affecting Qualcomm-based systems through the QCA_NL80211 vendor command interface. The flaw manifests when processing the QCA_NL80211_VENDOR_SUBCMD_GET_CHAIN_RSSI command where the QCA_WLAN_VENDOR_ATTR_MAC_ADDR attribute fails to contain the expected 6-byte MAC address format. This insufficient validation creates a critical buffer overrun condition that can be exploited by malicious actors to execute arbitrary code or cause system instability.
The technical implementation of this vulnerability stems from inadequate input validation within the wireless subsystem driver code. When the kernel receives a vendor command with a malformed MAC address attribute, it attempts to copy the insufficient data into a buffer allocated for a full 6-byte MAC address structure. This classic buffer overflow scenario occurs because the code does not properly verify the attribute length before performing memory operations, allowing an attacker to overwrite adjacent memory locations with crafted data. The vulnerability specifically impacts the wireless networking stack and can be triggered through specially crafted wireless management frames or vendor-specific commands sent to the system.
The operational impact of this vulnerability extends beyond simple system crashes, potentially enabling privilege escalation and remote code execution in affected systems. Attackers could exploit this flaw to gain elevated privileges within the kernel space, allowing them to manipulate system resources, access sensitive data, or maintain persistent control over affected devices. The vulnerability affects a broad range of devices including smartphones, tablets, and IoT systems running the affected Android and Firefox OS variants, making it particularly concerning for mobile device security. According to CWE classification, this represents a buffer overflow vulnerability (CWE-121) with potential privilege escalation implications.
Mitigation strategies for this vulnerability require immediate patching of the affected kernel versions and implementation of proper input validation mechanisms. Device manufacturers should ensure that all wireless subsystem components properly validate attribute lengths before processing vendor commands, implementing strict bounds checking for MAC address attributes. The fix should enforce minimum length requirements for the QCA_WLAN_VENDOR_ATTR_MAC_ADDR field and reject commands with insufficient data. Additionally, system administrators should monitor for unauthorized wireless management frame traffic and implement network segmentation to limit potential exploitation vectors. This vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and represents a critical kernel-level exploit that requires immediate remediation across all affected platforms. The vulnerability demonstrates the importance of proper input validation in kernel space drivers and highlights the need for comprehensive security testing of wireless subsystem implementations.