CVE-2017-9712 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, if userspace provides a too-large IE length in wlan_hdd_cfg80211_set_ie, a buffer over-read occurs.
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Analysis
by VulDB Data Team • 12/22/2019
This vulnerability exists in Android-based systems utilizing the Linux kernel from Code Aurora Forum with specific wireless networking components. The flaw manifests when userspace applications provide an excessively large IE (Information Element) length parameter to the wlan_hdd_cfg80211_set_ie function within the wireless driver implementation. This buffer over-read condition occurs because the system fails to properly validate the incoming IE length parameter before processing it, creating a potential pathway for memory corruption. The vulnerability specifically affects devices running Android for MSM, Firefox OS for MSM, and QRD Android versions that utilize Linux kernel implementations from CAF. The improper input validation allows attackers to craft malicious wireless configuration data that triggers the over-read behavior when the wireless subsystem processes these malformed parameters. This represents a classic buffer over-read vulnerability that can lead to unpredictable system behavior, potential information disclosure, or even remote code execution depending on the exploitation context.
The technical implementation of this vulnerability stems from insufficient bounds checking within the wireless configuration handling code. When userspace applications pass an IE length that exceeds the expected buffer boundaries, the wlan_hdd_cfg80211_set_ie function attempts to read beyond allocated memory regions. This over-read can expose sensitive kernel memory contents to userspace applications, potentially revealing stack contents, kernel addresses, or other confidential information. The vulnerability is particularly concerning because it operates at the kernel level within the wireless subsystem, where such memory access violations can compromise the entire system integrity. The attack vector involves sending specially crafted wireless configuration parameters to the affected wireless driver, which then processes these parameters without adequate validation of the IE length field. This flaw directly maps to CWE-125, which describes out-of-bounds read vulnerabilities, and can be categorized under ATT&CK technique T1059.007 for kernel-level command execution through memory corruption.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable more sophisticated attack scenarios. An attacker positioned within wireless range of a vulnerable device could potentially exploit this to gain unauthorized access to kernel memory, extract sensitive information such as encryption keys or system credentials, or even achieve privilege escalation. The vulnerability affects a broad range of devices including smartphones, tablets, and IoT devices that rely on the affected Linux kernel implementations. In enterprise environments, this could compromise wireless infrastructure security, particularly in scenarios where devices automatically connect to untrusted wireless networks. The exploitation requires minimal privileges as the vulnerability exists within kernel space processing, making it particularly dangerous for mobile platforms where users frequently connect to various wireless networks. This vulnerability aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel exploits, and represents a significant risk to mobile device security due to the widespread adoption of affected kernel implementations across various Android and Firefox OS devices.
Mitigation strategies for this vulnerability should focus on input validation and kernel memory protection mechanisms. System administrators should prioritize applying security patches from device manufacturers and Code Aurora Forum that implement proper bounds checking for IE length parameters. The recommended approach involves implementing strict validation of all incoming wireless configuration parameters before processing them within kernel space. Device vendors should enhance their wireless driver implementations to include comprehensive input sanitization and buffer overflow protection measures. Additionally, network administrators should consider implementing wireless network segmentation and monitoring to detect anomalous wireless configuration requests. The solution requires modifications to the wlan_hdd_cfg80211_set_ie function to validate the IE length parameter against maximum expected values, ensuring that memory access operations remain within allocated buffer boundaries. This vulnerability highlights the importance of secure coding practices in kernel-level wireless drivers and demonstrates the critical need for thorough input validation in all system components that handle external data. Organizations should also implement regular security assessments of their wireless infrastructure to identify and remediate similar vulnerabilities across their deployed device fleet.