CVE-2018-3574 in Android
Summary
by MITRE
In all android releases (Android for MSM, Firefox OS for MSM, QRD Android) from CAF using the linux kernel, userspace can request ION cache maintenance on a secure ION buffer for which the ION_FLAG_SECURE ion flag is not set and cause the kernel to attempt to perform cache maintenance on memory which does not belong to HLOS.
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Analysis
by VulDB Data Team • 05/17/2023
This vulnerability exists within the Linux kernel implementation of the ION memory management subsystem on Android devices manufactured by Qualcomm and other vendors. The issue stems from improper validation of memory buffer permissions during cache maintenance operations, specifically when userspace applications attempt to perform cache operations on buffers that lack the appropriate security flags. The vulnerability affects multiple Android variants including CAF Android, Firefox OS for MSM, and QRD Android platforms, indicating a widespread impact across Qualcomm-based devices.
The technical flaw occurs when a userspace process requests ION cache maintenance operations on memory buffers that have not been explicitly marked as secure using the ION_FLAG_SECURE flag. The kernel's cache maintenance routine fails to properly verify whether the requested memory operations are permitted for the specific buffer in question, leading to attempts to perform cache operations on memory regions that should remain protected from userspace access. This represents a classic privilege escalation vulnerability where userspace can bypass kernel security boundaries through improper access control validation.
The operational impact of this vulnerability is significant as it allows unauthorized userspace processes to potentially access or manipulate memory regions that should be restricted to the Hypervisor and kernel space. This could enable attackers to extract sensitive information from secure memory areas, modify critical system data, or potentially escalate privileges to gain full system control. The vulnerability particularly affects devices where the HLOS (High Level Operating System) memory protection mechanisms are intended to prevent userspace from accessing secure buffers, but the kernel's cache maintenance logic does not properly enforce these boundaries.
From a cybersecurity perspective, this vulnerability aligns with CWE-284 (Improper Access Control) and represents a privilege escalation vector that could be leveraged in combination with other exploits to achieve full system compromise. The ATT&CK framework would categorize this as a privilege escalation technique, specifically leveraging kernel vulnerabilities to gain elevated system access. The vulnerability demonstrates poor input validation and insufficient access control checks within kernel space operations, making it a prime target for exploitation by attackers seeking to bypass memory protection mechanisms.
Mitigation strategies should focus on implementing proper validation of ION buffer permissions before allowing cache maintenance operations, ensuring that only buffers explicitly marked as secure can undergo such operations. Kernel patches should enforce strict access control checks and prevent cache maintenance on memory regions that do not have appropriate security attributes. Additionally, system administrators should ensure timely deployment of vendor security updates and consider implementing additional runtime protections such as kernel address space layout randomization and memory protection mechanisms to reduce the exploitability of such vulnerabilities.