CVE-2019-9101 in MGate MB3170
Summary
by MITRE
An issue was discovered on Moxa MGate MB3170 and MB3270 devices before 4.1, MB3280 and MB3480 devices before 3.1, MB3660 devices before 2.3, and MB3180 devices before 2.1. Sensitive information is sent to the web server in cleartext, which may allow an attacker to discover the credentials if they are able to observe traffic between the web browser and the server.
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Analysis
by VulDB Data Team • 03/12/2020
The vulnerability identified as CVE-2019-9101 affects several Moxa MGate series industrial communication devices including MB3170, MB3270, MB3280, MB3480, MB3660, and MB3180 models. This security flaw represents a critical weakness in the network communication protocols implemented by these industrial IoT devices, which are commonly deployed in manufacturing environments for remote monitoring and control applications. The affected devices operate with firmware versions prior to specified thresholds, creating a persistent security risk that could compromise industrial control systems. The vulnerability stems from improper implementation of secure communication practices, specifically the transmission of sensitive data without adequate encryption mechanisms.
The technical flaw manifests as the cleartext transmission of sensitive information between web browsers and the affected web servers running on these industrial devices. This design weakness allows attackers positioned within the network to intercept and analyze traffic using standard packet sniffing tools or network monitoring utilities. The vulnerability directly violates fundamental security principles for protecting authentication credentials and other sensitive operational data. According to CWE-312, this represents a cleartext storage or transmission of sensitive information, while the ATT&CK framework categorizes this under T1071.004 for application layer protocol: web protocols where sensitive data is transmitted without encryption. The devices in question fail to implement proper TLS/SSL encryption for web-based administrative interfaces, leaving authentication tokens, passwords, and configuration data exposed to passive network monitoring.
The operational impact of this vulnerability extends beyond simple credential theft, potentially enabling sophisticated attack scenarios that could disrupt industrial operations or compromise physical security systems. An attacker who successfully intercepts the cleartext credentials could gain unauthorized access to device management interfaces, allowing them to modify configurations, disable security features, or escalate privileges within the industrial network. The affected devices are commonly used in critical infrastructure environments where unauthorized access could lead to production disruptions, safety hazards, or data breaches. The vulnerability is particularly concerning because it affects multiple device models across different generations, indicating a systemic design flaw rather than an isolated incident. Network administrators may not immediately detect credential compromise since the traffic appears legitimate, making this attack vector particularly stealthy and difficult to identify through conventional monitoring approaches.
Organizations should implement immediate mitigations including network segmentation to isolate affected devices from critical systems, deployment of network intrusion detection systems to monitor for suspicious traffic patterns, and enforcement of secure remote access protocols such as VPN connections. The most effective long-term solution involves updating all affected devices to the latest firmware versions provided by Moxa, which include proper encryption implementations. Security teams should also consider implementing network access controls using firewalls and access control lists to restrict direct web access to these devices. According to NIST SP 800-53 security controls, organizations must ensure proper network security and information protection measures are in place. Additionally, regular vulnerability assessments and network monitoring should be conducted to identify and remediate similar weaknesses in other industrial control systems, as this vulnerability demonstrates the importance of secure communication protocols in industrial environments. The incident highlights the critical need for manufacturers to implement secure-by-design principles in industrial IoT devices, particularly when dealing with authentication and credential management systems.