CVE-2018-11906 in Android
Summary
by MITRE
In all android releases(Android for MSM, Firefox OS for MSM, QRD Android) from CAF using the linux kernel, there is a security concern with default privileged access to ADB and debug-fs.
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Analysis
by VulDB Data Team • 06/11/2023
The vulnerability identified as CVE-2018-11906 represents a critical privilege escalation issue affecting multiple Android variants including MSM-based devices, Firefox OS for MSM, and QRD Android implementations. This flaw stems from the Linux kernel's handling of Android Debug Bridge (ADB) and debug filesystem access controls, creating an unintended pathway for unauthorized privilege elevation. The vulnerability specifically targets the default configuration settings that govern how ADB and debug-fs are accessed within these Android implementations, allowing malicious actors to exploit these default permissions for unauthorized system access.
The technical root cause of this vulnerability lies in the improper implementation of access control mechanisms within the Linux kernel components that support Android's debugging infrastructure. When ADB and debug-fs are enabled by default, the system fails to properly enforce restrictive access controls that should limit administrative privileges to authorized users only. This misconfiguration creates a persistent security weakness where any user with physical access to the device can leverage these default privileges to gain elevated system access. The flaw operates at the kernel level where the system fails to validate the identity and authorization status of entities attempting to access debug filesystem interfaces, effectively bypassing the normal security boundaries that should protect privileged system resources.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential full system compromise and data exfiltration capabilities. Attackers can exploit this vulnerability to access sensitive system files, modify core system components, install malicious applications with elevated privileges, and potentially establish persistent backdoors. The vulnerability affects a broad range of devices including smartphones, tablets, and embedded systems that utilize the affected Android variants, making it particularly dangerous in enterprise and consumer environments. The default nature of the vulnerability means that affected systems are vulnerable without any user intervention or additional configuration changes, creating a widespread security risk across multiple device categories and manufacturers.
Security professionals should implement immediate mitigations including disabling ADB and debug-fs interfaces when not actively needed, implementing proper access control policies, and ensuring that device administrators configure secure default settings. Organizations should also conduct comprehensive vulnerability assessments to identify affected systems and implement network segmentation to limit potential exploitation. The vulnerability aligns with CWE-284 which addresses improper access control in software systems, and represents a significant concern from an ATT&CK framework perspective as it enables the T1059 command and control techniques by providing unauthorized access to system resources. Additionally, this vulnerability demonstrates the importance of secure configuration management and the principle of least privilege in mobile device security implementations.