CVE-2015-9146 in Android
Summary
by MITRE
In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile MDM9625, MDM9635M, MDM9645, MDM9650, MDM9655, SD 400, SD 800, SD 835, SD 845, SD 850, and SDX20, when QDI read, write, or ioctl are called, the passed-in pointer is not properly validated before accessing it for the delayed response.
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Analysis
by VulDB Data Team • 01/26/2020
This vulnerability exists in Qualcomm Snapdragon mobile chipsets affecting Android devices released before the 2018-04-05 security patch level. The issue resides in the QDI (Qualcomm Device Interface) subsystem where the kernel driver fails to properly validate pointers before accessing them during read, write, or ioctl operations. This represents a classic buffer overread or use-after-free scenario that can be exploited by malicious actors to gain unauthorized access to system resources. The vulnerability affects multiple Snapdragon variants including the MDM9625, MDM9635M, MDM9645, MDM9650, MDM9655, SD 400, SD 800, SD 835, SD 845, SD 850, and SDX20 chipsets, indicating a widespread impact across Qualcomm's mobile platform portfolio.
The technical flaw stems from inadequate input validation within the QDI driver implementation where kernel-space code processes user-supplied pointers without proper bounds checking or null validation. When the system executes read, write, or ioctl commands through the QDI interface, the driver directly dereferences the passed-in pointer without verifying its validity or ensuring proper memory alignment. This allows attackers to craft malicious input that can cause the kernel to access arbitrary memory locations or trigger privilege escalation conditions. The vulnerability is categorized as a memory safety issue that aligns with CWE-125 (Out-of-bounds Read) and CWE-787 (Out-of-bounds Write) classifications, representing a critical weakness in kernel driver security.
The operational impact of this vulnerability is significant as it can be leveraged by attackers to achieve privilege escalation from user mode to kernel mode execution. An attacker could potentially exploit this weakness to execute arbitrary code with kernel privileges, access sensitive system data, or modify critical system components. The delayed response mechanism mentioned in the description suggests that the vulnerability might be triggered through a sequence of operations rather than a single call, making detection more challenging for security monitoring systems. This type of vulnerability falls under ATT&CK technique T1068 (Exploitation for Privilege Escalation) and T1059 (Command and Scripting Interpreter) as it enables attackers to gain elevated privileges and execute malicious code within the kernel space.
Mitigation strategies should focus on applying the latest security patches provided by Qualcomm and Android vendors, which include proper pointer validation mechanisms and input sanitization within the QDI driver components. Device manufacturers should implement kernel memory protection features such as stack canaries, kernel address space layout randomization, and memory integrity checking. Additionally, security researchers should monitor for similar patterns in other Qualcomm driver components and implement defensive programming practices including thorough pointer validation, bounds checking, and proper error handling. Organizations should also consider implementing runtime monitoring solutions that can detect anomalous kernel behavior patterns associated with memory corruption exploits. The vulnerability demonstrates the critical importance of secure kernel driver development practices and proper input validation in mobile security architectures, particularly in the context of hardware-software integration where low-level drivers can provide attack vectors for privilege escalation.