CVE-2015-9033 in Android
Summary
by MITRE
In all Android releases from CAF using the Linux kernel, a QTEE system call fails to validate a pointer.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2015-9033 represents a critical security flaw within the Qualcomm Trusted Execution Environment (QTEE) system call implementation in Android devices running Linux kernel versions from the Code Aurora Forum. This vulnerability resides in the kernel-level subsystem responsible for handling trusted execution environments and secure processing operations. The flaw manifests when the QTEE system call processes incoming pointer parameters without proper validation, creating a potential pathway for malicious code execution or privilege escalation within the secure environment.
This technical vulnerability falls under the category of improper input validation as classified by CWE-20, specifically involving the failure to validate pointers in system call interfaces. The QTEE subsystem operates as a separate secure processing environment that handles sensitive operations such as cryptographic key management, secure boot processes, and hardware-based security functions. When a system call fails to validate pointer inputs, it creates an opportunity for attackers to manipulate memory references and potentially execute arbitrary code within the trusted execution environment.
The operational impact of CVE-2015-9033 extends beyond simple privilege escalation to encompass potential compromise of the entire secure execution environment. Attackers could exploit this vulnerability to gain unauthorized access to cryptographic keys, sensitive data processing capabilities, or hardware security modules that are normally isolated from regular operating system processes. This vulnerability affects all Android releases utilizing CAF kernels, making it particularly concerning as it impacts a wide range of devices including smartphones, tablets, and other mobile platforms that rely on Qualcomm's secure execution capabilities. The exploitation of this flaw could enable attackers to bypass hardware-based security measures and access sensitive information that should remain protected within the trusted execution environment.
Mitigation strategies for CVE-2015-9033 should focus on implementing proper pointer validation mechanisms within the QTEE system call interface, ensuring that all incoming memory references are properly validated before processing. System administrators and device manufacturers should prioritize applying security patches that address the pointer validation flaw in the kernel implementation. Additionally, implementing runtime protections such as stack canaries, address space layout randomization, and kernel address space protection can provide additional defense-in-depth measures. The vulnerability also highlights the importance of secure coding practices in kernel-level system calls and the necessity of comprehensive input validation for all external interfaces. Organizations should also consider monitoring for unusual system call patterns that might indicate exploitation attempts against the QTEE subsystem, as outlined in various ATT&CK framework techniques related to kernel-mode exploitation and privilege escalation.