CVE-2016-10406 in Android
Summary
by MITRE
In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile MDM9650, SD 210/SD 212/SD 205, SD 410/12, SD 430, SD 450, SD 615/16/SD 415, SD 617, SD 625, SD 650/52, SD 808, SD 810, SD 820, and SD 835, while printing debug message of a pointer in wlan_qmi_err_cb, the real kernel address will be printed regardless of the kptr_restrict system settings.
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Analysis
by VulDB Data Team • 01/27/2020
This vulnerability exists in Qualcomm Snapdragon mobile chipsets affecting Android devices with security patch levels prior to 2018-04-05. The issue manifests in the wlan_qmi_err_cb function where debug messages containing pointer values are printed without proper kernel address sanitization. This flaw allows attackers to potentially extract kernel memory addresses from the device, which can be leveraged for advanced exploitation techniques. The vulnerability affects a wide range of Snapdragon SoCs including the MDM9650, SD 210/SD 212/SD 205, SD 410/12, SD 430, SD 450, SD 615/16/SD 415, SD 617, SD 625, SD 650/52, SD 808, SD 810, SD 820, and SD 835 chipsets. The root cause stems from improper handling of kernel pointer values during debug output operations, bypassing the kptr_restrict system protection mechanism that normally obscures kernel addresses. This vulnerability directly relates to CWE-209, which addresses the exposure of sensitive information through error messages, and represents a significant information disclosure risk that can facilitate further exploitation attempts. The flaw is particularly concerning because it operates at the kernel level where debug information is typically restricted to prevent information leakage that could aid in kernel exploitation techniques.
The technical implementation of this vulnerability occurs when the wlan_qmi_err_cb callback function processes error conditions in the wireless module. During error handling, the function prints debug information that includes raw pointer values without applying the kptr_restrict protection. This means that even when the system is configured to hide kernel addresses through kptr_restrict settings, the vulnerability allows direct exposure of these addresses in debug logs. The exploitation potential arises from the fact that kernel addresses can be used to bypass kernel address space layout randomization defenses, which are critical security mechanisms that randomize memory layout to prevent predictable memory access patterns. Attackers could leverage this information disclosure to craft more sophisticated attacks targeting kernel memory structures, potentially leading to privilege escalation or system compromise. The vulnerability essentially undermines the kernel's memory protection mechanisms by providing direct access to kernel virtual addresses that should normally remain hidden from user-space processes and debug output.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to gather critical kernel memory layout information that can be used in advanced exploitation techniques. This information leakage can be particularly damaging in targeted attacks where adversaries need to understand the kernel memory structure to perform successful exploitation. The vulnerability affects devices running on Qualcomm Snapdragon chipsets that were shipped with Android versions prior to the 2018-04-05 security patch, making it a widespread issue across numerous mobile devices. The security implications are significant because kernel address disclosure can enable attackers to perform return-oriented programming attacks, kernel code injection, or other advanced exploitation techniques that rely on knowledge of kernel memory layout. This vulnerability also aligns with ATT&CK technique T1059.007 for kernel exploits and T1068 for privilege escalation, as it provides the information necessary to bypass memory protection mechanisms. The exposure of kernel addresses can also be combined with other vulnerabilities to create more effective attack vectors, particularly when combined with memory corruption vulnerabilities that require precise address knowledge.
Mitigation strategies for this vulnerability focus primarily on applying the relevant security patches released by Qualcomm and Android vendors. The recommended solution is to update devices to security patch levels released on or after 2018-04-05, which contain fixes for the wlan_qmi_err_cb function that properly sanitize pointer values before debug output. System administrators and device manufacturers should ensure that all affected Snapdragon chipsets receive the appropriate firmware and software updates. Additionally, organizations should implement monitoring for suspicious debug log patterns that might indicate exploitation attempts. The fix typically involves modifying the wlan_qmi_err_cb function to properly mask or sanitize pointer values before they are printed in debug messages, ensuring that kernel addresses are not exposed regardless of the kptr_restrict system settings. While this vulnerability represents a kernel-level information disclosure issue, it can be effectively addressed through proper patch management and system updates. Device manufacturers should also consider implementing additional logging controls to prevent the exposure of sensitive kernel information in debug contexts. The vulnerability demonstrates the importance of secure coding practices in kernel modules, particularly regarding debug output handling and information disclosure prevention.