CVE-2017-14437 in EDR-810
Summary
by MITRE
An exploitable denial of service vulnerability exists in the web server functionality of Moxa EDR-810 V4.1 build 17030317. A specially crafted HTTP URI can cause a null pointer dereference resulting in denial of service. An attacker can send a GET request to "/MOXA\_LOG.ini" without a cookie header to trigger this vulnerability.
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Analysis
by VulDB Data Team • 03/13/2023
The vulnerability identified as CVE-2017-14437 represents a critical denial of service weakness within the Moxa EDR-810 industrial network device running firmware version V4.1 build 17030317. This issue specifically affects the web server component of the device, which serves as the primary interface for remote administration and monitoring operations in industrial environments. The Moxa EDR-810 is designed for industrial automation and remote monitoring applications where continuous availability is paramount for operational integrity. The vulnerability stems from inadequate input validation within the HTTP request processing pipeline, particularly when handling specific URI patterns that are commonly used for system logging and configuration access.
The technical flaw manifests as a null pointer dereference condition that occurs when the web server processes HTTP GET requests targeting the "/MOXA_LOG.ini" endpoint. This particular URI path is typically used to access system log configuration files, but the implementation fails to properly validate the presence of required HTTP headers before attempting to process the request. When an attacker sends a GET request to this specific endpoint without including a cookie header, the web server's internal processing logic attempts to dereference a null pointer variable that should have been initialized or validated. This programming error, classified under CWE-476 as Null Pointer Dereference, causes the web server process to crash and terminate unexpectedly, leading to complete denial of service for the device's web interface.
The operational impact of this vulnerability extends beyond simple service interruption, particularly in industrial control systems where device availability directly affects production processes and operational safety. The Moxa EDR-810 serves as a critical communication gateway in industrial networks, facilitating data exchange between field devices and central monitoring systems. When the web server becomes unavailable due to this denial of service attack, administrators lose the ability to monitor device status, configure settings, or troubleshoot issues remotely. This limitation can compound into larger operational disruptions when maintenance personnel cannot access device configuration interfaces during critical system events or when automated monitoring systems rely on web-based APIs for status reporting.
The vulnerability demonstrates a classic weakness in industrial device security where basic input validation mechanisms are insufficient to prevent malformed requests from causing system instability. The attack vector is particularly concerning because it requires minimal sophistication to execute, making it accessible to threat actors with basic network reconnaissance capabilities. The specific nature of the exploit, targeting a well-known configuration file path, suggests that attackers could potentially use this vulnerability as part of broader reconnaissance activities to identify vulnerable industrial devices within network scopes. Security practitioners should consider this vulnerability in the context of ATT&CK framework's T1499 technique for network disruption, as it enables attackers to perform denial of service attacks against industrial control systems.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from Moxa to address the underlying null pointer dereference issue. Network segmentation and access control measures should be implemented to limit exposure of industrial devices to untrusted networks, particularly restricting direct access to web management interfaces from external networks. The implementation of intrusion detection systems with signature-based detection for this specific attack pattern can provide early warning of exploitation attempts. Additionally, organizations should consider implementing redundant monitoring and management interfaces to ensure continued operational capability even when primary web interfaces become unavailable. Regular security assessments of industrial control systems should include verification of firmware versions and patch status to prevent similar vulnerabilities from remaining unaddressed in operational environments.