CVE-2017-18055 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, improper input validation for wmi_event->num_vdev_mac_entries in wma_pdev_set_hw_mode_resp_evt_handler(), which is received from firmware, leads to potential buffer overflow.
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Analysis
by VulDB Data Team • 02/22/2023
This vulnerability exists within the Android operating system and related mobile platforms that utilize the Linux kernel through the Qualcomm Android Framework. The flaw specifically resides in the wireless management subsystem where firmware communicates hardware mode configuration responses to the host system. The issue manifests in the wma_pdev_set_hw_mode_resp_evt_handler() function which processes incoming wmi_event structures containing hardware mode configuration data. The vulnerability stems from inadequate validation of the num_vdev_mac_entries field within the wmi_event structure, which is populated directly from firmware responses without proper bounds checking or sanitization.
The technical implementation of this vulnerability allows for a classic buffer overflow condition when the number of virtual device MAC entries exceeds allocated buffer space. This occurs because the system assumes the firmware will provide valid data without verification, creating an opportunity for malicious actors to craft specially crafted firmware responses that exceed expected buffer boundaries. The flaw is particularly concerning as it operates at the kernel level within the wireless management driver, providing potential attackers with elevated privileges and system compromise capabilities. This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and represents a critical security gap in the input validation mechanisms of the wireless subsystem.
The operational impact of this vulnerability extends beyond simple buffer corruption, as it enables potential remote code execution and system compromise when exploited. An attacker with access to the wireless communication channel or ability to inject malicious firmware responses could trigger the overflow condition, potentially leading to complete system takeover. The vulnerability affects multiple Android variants including MSM, Firefox OS, and QRD Android platforms, indicating a widespread exposure across Qualcomm-based mobile devices. This creates a significant risk for enterprise environments and consumer devices where wireless connectivity is essential, as the attack surface includes both local and remote exploitation vectors.
Mitigation strategies should focus on implementing robust input validation mechanisms within the wireless management subsystem, including bounds checking for all firmware-provided data structures. The recommended approach involves adding proper validation routines that verify the num_vdev_mac_entries field against predetermined maximum limits before processing. Security patches should be implemented to ensure that all incoming wmi_event structures undergo comprehensive sanitization before being used in memory operations. Additionally, system administrators should monitor for unauthorized firmware updates and implement network segmentation to limit potential attack vectors. The vulnerability demonstrates the importance of adhering to secure coding practices as outlined in the ATT&CK framework's defensive techniques, particularly those related to input validation and privilege separation. Regular security assessments and firmware update management procedures should be strengthened to prevent exploitation of similar vulnerabilities in the wireless subsystem.