CVE-2018-5449 in OnCell G3100-HSPA
Summary
by MITRE
A NULL Pointer Dereference issue was discovered in Moxa OnCell G3100-HSPA Series version 1.4 Build 16062919 and prior. The application does not check for a NULL value, allowing for an attacker to perform a denial of service attack.
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Analysis
by VulDB Data Team • 01/10/2020
The CVE-2018-5449 vulnerability represents a critical null pointer dereference flaw in Moxa OnCell G3100-HSPA Series devices running firmware version 1.4 Build 16062919 and earlier. This vulnerability resides within the device's network communication handling mechanisms, specifically in the processing of incoming data packets or configuration requests. The flaw occurs when the application fails to validate pointer references before attempting to access memory locations, creating an exploitable condition that can be leveraged by remote attackers. The vulnerability is classified under CWE-476 as a NULL Pointer Dereference, which is a well-documented weakness in software development practices where programs fail to check for null values before dereferencing pointers. This particular implementation flaw affects the device's ability to process legitimate network traffic and system commands, ultimately leading to a denial of service condition that can render the entire device inoperable.
The operational impact of this vulnerability extends beyond simple service interruption, as it represents a fundamental flaw in the device's error handling and input validation mechanisms. When an attacker crafts malicious network packets or configuration commands that trigger the null pointer dereference, the device's process crashes and subsequently fails to recover automatically, requiring manual intervention and device reboot to restore functionality. The vulnerability is particularly concerning for industrial IoT deployments where these devices serve as critical communication endpoints for remote monitoring and control systems. Network attackers can exploit this weakness without requiring authentication credentials, making it a high-severity threat for any organization relying on these devices for network connectivity or remote management. The device's lack of proper error handling and recovery mechanisms means that a single successful exploit can cause prolonged service disruption, potentially affecting critical infrastructure operations.
Security practitioners should implement immediate mitigations including firmware updates from Moxa to address the null pointer dereference issue, network segmentation to limit exposure of these devices to untrusted networks, and monitoring for anomalous network traffic patterns that may indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1499.004 for network denial of service attacks and represents a classic example of insufficient input validation that can be prevented through proper defensive programming practices. Organizations should also consider implementing intrusion detection systems to monitor for known exploit patterns targeting this specific vulnerability, as well as establishing incident response procedures for device recovery and forensic analysis. The device manufacturer's security advisory should be consulted for specific patch details and implementation guidance, while network administrators should conduct thorough vulnerability assessments to identify all affected devices within their infrastructure. Regular firmware updates and security audits become essential practices to prevent similar vulnerabilities from compromising operational technology systems in industrial environments.