CVE-2015-0570 in Android
Summary
by MITRE
Stack-based buffer overflow in the SET_WPS_IE IOCTL implementation in wlan_hdd_hostapd.c in the WLAN (aka Wi-Fi) driver for the Linux kernel 3.x and 4.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, allows attackers to gain privileges via a crafted application that uses a long WPS IE element.
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Analysis
by VulDB Data Team • 07/27/2022
The vulnerability described in CVE-2015-0570 represents a critical stack-based buffer overflow within the wireless local area network driver implementation of the Linux kernel. This flaw exists specifically within the SET_WPS_IE IOCTL (Input/Output Control) handler located in the wlan_hdd_hostapd.c file, which is part of the Qualcomm Innovation Center's Android contributions for MSM (Mobile Station Modem) devices. The vulnerability affects kernel versions 3.x and 4.x, making it particularly concerning as these versions encompass a broad range of Android device implementations. The issue manifests when a malicious application attempts to exploit the WPS (Wi-Fi Protected Setup) IE (Information Element) processing functionality through a crafted IOCTL call with an excessively long WPS IE element, ultimately leading to privilege escalation capabilities.
The technical mechanism behind this vulnerability stems from improper bounds checking within the wireless driver's implementation of the SET_WPS_IE command. When a WPS IE element is processed, the driver fails to validate the length of the input data against the allocated stack buffer size, creating a classic stack-based buffer overflow condition. This flaw aligns with CWE-121, which specifically addresses stack-based buffer overflow conditions, and demonstrates how insufficient input validation can lead to memory corruption. The buffer overflow occurs during the handling of the WPS IE element, where the driver copies user-supplied data into a fixed-size stack buffer without adequate length verification, allowing attackers to overwrite adjacent stack memory and potentially execute arbitrary code with kernel-level privileges.
The operational impact of CVE-2015-0570 is severe and multifaceted, as it enables attackers to achieve privilege escalation from a regular application context to kernel-level privileges. This elevation of privileges allows malicious actors to bypass Android's security model entirely, gaining access to sensitive system resources, modifying system files, accessing encrypted data, and potentially establishing persistent backdoors. The vulnerability's exploitation requires only a crafted application, making it particularly dangerous as it can be triggered through seemingly benign user interactions or malicious app installations. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and represents a prime example of how kernel-level vulnerabilities can be leveraged for complete system compromise. The widespread adoption of Qualcomm's MSM-based wireless drivers across various Android devices amplifies the potential attack surface significantly.
Mitigation strategies for CVE-2015-0570 must address both immediate remediation and long-term security improvements. The primary and most effective solution involves applying kernel patches that implement proper bounds checking for the WPS IE element length validation within the SET_WPS_IE IOCTL handler. These patches should enforce strict input validation to prevent buffer overflows by ensuring that WPS IE elements do not exceed the allocated buffer size. Additionally, system administrators and device manufacturers should implement kernel hardening measures such as stack canaries, address space layout randomization, and kernel address space layout randomization to make exploitation more difficult. Security researchers should also consider implementing runtime protections and monitoring for suspicious IOCTL calls that attempt to manipulate WPS IE elements with unusually long data payloads. The vulnerability serves as a reminder of the critical importance of input validation in kernel space code and demonstrates how seemingly minor implementation flaws can result in complete system compromise, emphasizing the need for comprehensive security testing and code review processes in kernel driver development.