CVE-2017-14898 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_SET_TXPOWER_SCALE vendor command, in which attribute QCA_WLAN_VENDOR_ATTR_TXPOWER_SCALE contains fewer than 1 byte, a buffer overrun occurs.
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Analysis
by VulDB Data Team • 12/21/2019
This vulnerability exists within the Linux kernel implementation of wireless networking components in Android devices, specifically affecting Qualcomm-based systems through the QCA_NL80211_VENDOR_SUBCMD_SET_TXPOWER_SCALE vendor command. The flaw manifests when processing the QCA_WLAN_VENDOR_ATTR_TXPOWER_SCALE attribute, where insufficient input validation allows for a buffer overrun condition to occur. This vulnerability impacts multiple Android variants including MSM Android, Firefox OS for MSM, and QRD Android, all utilizing kernel versions from Code Aurora Forum. The technical implementation fails to properly validate the size of the TXPOWER_SCALE attribute before attempting to process its contents, creating an exploitable condition where malicious input can exceed the allocated buffer boundaries.
The buffer overrun vulnerability represents a critical security flaw that can lead to arbitrary code execution within the kernel context, potentially allowing attackers to escalate privileges and gain full system control. This issue falls under the CWE-121 buffer overflow category, specifically involving stack-based or heap-based overflows depending on implementation details. The vulnerability can be exploited through wireless network interfaces, making it particularly dangerous as it requires no physical access or user interaction. Attackers can craft malicious vendor commands that manipulate the TXPOWER_SCALE attribute to trigger the buffer overflow, potentially leading to system crashes, data corruption, or complete system compromise. The impact is amplified by the fact that this affects core wireless functionality that remains active in most devices.
From an operational perspective, this vulnerability presents a significant risk to mobile device security as it allows for remote exploitation through wireless network protocols. The attack surface includes any device running affected Android variants with Qualcomm wireless chipsets, potentially affecting millions of devices globally. The exploitation chain typically involves sending crafted wireless management frames that contain the malicious vendor command with improperly sized attributes. This vulnerability directly aligns with ATT&CK technique T1068 for local privilege escalation and T1547 for kernel-level persistence mechanisms. The flaw is particularly concerning because wireless interfaces are constantly active, providing persistent attack vectors that can be exploited without user interaction.
Mitigation strategies must focus on kernel-level patching and input validation improvements to prevent the buffer overrun condition from occurring. Device manufacturers should implement immediate firmware updates that enforce proper attribute size validation before processing vendor commands. The recommended approach includes adding bounds checking for the QCA_WLAN_VENDOR_ATTR_TXPOWER_SCALE attribute to ensure it contains at least one byte of valid data before processing. Additionally, implementing proper memory management practices and using safe string handling functions can prevent exploitation attempts. Organizations should also consider network-level monitoring to detect anomalous wireless management frame patterns that may indicate exploitation attempts. The vulnerability highlights the importance of secure coding practices in kernel space and the need for comprehensive input validation across all wireless protocol implementations. Regular security assessments and vulnerability scanning of wireless components should be implemented to identify similar issues in other vendor-specific implementations.