CVE-2018-9369 in Android
Summary
by MITRE • 11/19/2024
In bootloader there is fastboot command allowing user specified kernel command line arguments. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.
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Analysis
by VulDB Data Team • 11/19/2024
The vulnerability identified as CVE-2018-9369 resides within the bootloader implementation of certain mobile devices, specifically affecting the fastboot interface which provides a mechanism for flashing and modifying device firmware. This flaw represents a critical security weakness that enables local privilege escalation through the manipulation of kernel command line arguments during the boot process. The vulnerability manifests when the bootloader fails to properly validate or sanitize user-provided kernel parameters, creating an avenue for malicious actors to inject arbitrary command line arguments that can alter system behavior and potentially elevate privileges.
The technical implementation of this vulnerability stems from insufficient input validation within the fastboot command execution flow. When users or applications invoke specific fastboot commands that allow kernel parameter modification, the system does not adequately verify the legitimacy or safety of these parameters before they are passed to the kernel. This design flaw aligns with CWE-20, which addresses improper input validation, and represents a classic example of command injection vulnerability in firmware contexts. The vulnerability is particularly concerning because it operates at the bootloader level, which is typically executed with high privileges and before the operating system fully initializes, making it an attractive target for attackers seeking to establish persistent control over device operations.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to modify critical system parameters that govern kernel behavior, memory management, and device access controls. An attacker who successfully exploits this vulnerability can manipulate kernel command line arguments to disable security features such as kernel address space layout randomization, enable debug interfaces, or modify device permissions in ways that compromise the entire system integrity. The requirement for user interaction indicates that exploitation typically involves physical access to the device or the ability to execute specific fastboot commands through legitimate interfaces, but once triggered, the attack can persist across reboots and potentially provide a foothold for more sophisticated attacks. This vulnerability directly relates to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and T1059, 'Command and Scripting Interpreter', as it leverages legitimate system interfaces to execute malicious commands.
Mitigation strategies for CVE-2018-9369 should focus on implementing robust input validation and sanitization within the bootloader's fastboot command processing. Device manufacturers should ensure that all kernel command line arguments passed through fastboot interfaces undergo strict validation to prevent injection of malicious parameters. Security patches should include enhanced parameter filtering mechanisms that reject potentially dangerous kernel arguments, particularly those that could modify security-relevant kernel features. Additionally, implementing secure boot mechanisms and cryptographic verification of bootloader components can prevent unauthorized modifications to the boot process. Organizations should also consider restricting access to fastboot interfaces in production environments and implementing proper access controls to limit who can execute fastboot commands. The vulnerability highlights the importance of firmware security testing and the need for comprehensive security reviews of low-level system interfaces that operate outside the normal operating system security boundaries, as these components often represent critical attack surfaces that can provide persistent access to device functionality.