CVE-2018-9386 in Android
Summary
by MITRE • 12/06/2024
In reboot_block_command of htc reboot_block driver, there is a possible stack buffer overflow due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2018-9386 resides within the htc reboot_block driver component of Android systems, specifically in the reboot_block_command function where a stack buffer overflow condition can occur. This flaw represents a critical security weakness that stems from inadequate input validation mechanisms within the kernel-level driver code. The issue manifests when the driver processes incoming commands without performing proper bounds checking on the data buffer, creating an exploitable condition that allows malicious code to overwrite adjacent stack memory locations. The vulnerability is classified under CWE-121 Stack-based Buffer Overflow, which is a well-documented weakness category that directly impacts the integrity of memory management in kernel space operations.
The technical implementation of this vulnerability involves a scenario where user-supplied data is copied into a fixed-size stack buffer without verification of its length against the buffer boundaries. When the input exceeds the allocated buffer size, it overflows into adjacent memory regions, potentially corrupting the stack frame and allowing an attacker to manipulate the execution flow. The exploitation requires only local privileges since the vulnerability exists within a system-level driver that operates with elevated permissions. The absence of user interaction requirements makes this particularly concerning as it can be triggered through automated means without requiring physical access or additional attack vectors. This characteristic aligns with ATT&CK technique T1068, which describes the exploitation of legitimate system processes to gain elevated privileges.
The operational impact of CVE-2018-9386 extends beyond simple privilege escalation to encompass potential system compromise and data integrity violations. An attacker with local access can leverage this vulnerability to execute arbitrary code with system-level privileges, effectively bypassing normal security restrictions and potentially gaining complete control over the affected device. The vulnerability affects devices running Android versions prior to the patch release, making it particularly relevant for older smartphone models and tablets that may not receive regular security updates. The stack buffer overflow creates opportunities for attackers to inject malicious code, modify system parameters, or establish persistent access mechanisms that could remain undetected for extended periods. This type of vulnerability directly impacts the Android security model and represents a failure in the kernel driver's memory management practices.
Mitigation strategies for CVE-2018-9386 should focus on immediate patch deployment and system hardening measures to prevent exploitation. Device manufacturers and security teams should prioritize updating affected Android versions to include proper bounds checking mechanisms in the reboot_block_command function. The implementation of stack canaries, address space layout randomization, and other exploit prevention techniques can provide additional layers of protection against similar vulnerabilities. System administrators should also monitor for suspicious kernel-level activity and implement runtime protections to detect anomalous behavior that might indicate exploitation attempts. The vulnerability serves as a reminder of the importance of proper input validation in kernel-space code and highlights the need for comprehensive security testing of device drivers before deployment. Regular security audits of kernel components and adherence to secure coding practices can help prevent similar issues from emerging in future software releases.