CVE-2017-14436 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\_CFG2.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-2017-14436 represents a critical denial of service weakness within the Moxa EDR-810 industrial network security appliance running firmware version V4.1 build 17030317. This device operates as a web server component within industrial environments, providing configuration and management interfaces for network security operations. The flaw manifests specifically within the HTTP URI handling mechanism when processing requests directed to the "/MOXA_CFG2.ini" endpoint, making it particularly dangerous for operational technology systems where continuous availability is paramount.
The technical exploitation of this vulnerability stems from a null pointer dereference condition that occurs when the web server processes HTTP GET requests to the designated URI without the required cookie header. This particular flaw falls under the CWE-476 category of NULL Pointer Dereference, where the application fails to properly validate input parameters before attempting to access memory locations. The absence of cookie header validation creates a scenario where the server's internal pointer management becomes compromised, leading to an unhandled exception that terminates the web server process. This behavior aligns with ATT&CK technique T1499.004 for Network Denial of Service, where adversaries leverage application-level weaknesses to disrupt services.
The operational impact of this vulnerability extends beyond simple service interruption, as it specifically targets the configuration management interface of industrial security appliances. In environments where Moxa EDR-810 devices serve as critical network gateways or security appliances, a successful exploit could result in complete loss of administrative access and configuration capabilities. The vulnerability's exploitation requires minimal effort from attackers, who only need to send a single HTTP GET request to trigger the denial of service condition. This makes it particularly attractive for malicious actors seeking to disrupt industrial control systems or network security operations, especially in sectors such as manufacturing, energy, and critical infrastructure where these devices are commonly deployed.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from Moxa to address the underlying null pointer dereference issue. Organizations should also implement network segmentation and access controls to limit exposure to this specific endpoint, while monitoring for unauthorized access attempts to the affected URI. Additionally, security teams should consider implementing intrusion detection systems capable of identifying and blocking malicious requests to the "/MOXA_CFG2.ini" endpoint. The remediation process should include comprehensive testing of updated firmware in non-production environments before deployment to ensure no regression issues arise. Organizations operating in regulated environments should also document this vulnerability and its remediation as part of their cybersecurity compliance requirements, particularly when dealing with industrial control systems where availability and integrity of network security devices are critical for overall system security.