CVE-2019-20481 in XGW 3000 ZigBee Gateway
Summary
by MITRE
In MIELE XGW 3000 ZigBee Gateway before 2.4.0, the Password Change Function does not require knowledge of the old password. This can be exploited in conjunction with CVE-2019-20480.
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Analysis
by VulDB Data Team • 05/12/2025
The MIELE XGW 3000 ZigBee Gateway represents a smart home networking device that facilitates communication between various IoT appliances and central control systems within residential and commercial environments. This particular gateway serves as a critical component in the MIELE ecosystem, managing wireless connectivity for kitchen appliances and other smart devices through ZigBee protocol standards. The device operates as a bridge between local IoT networks and cloud services, making it a potentially attractive target for attackers seeking to compromise home automation systems. Security vulnerabilities in such devices can have cascading effects on overall home network security and may provide attackers with persistent access to connected smart appliances.
The vulnerability identified as CVE-2019-20481 specifically targets the password change functionality within the gateway's web interface. This flaw represents a classic authentication bypass issue where the system fails to enforce proper password verification mechanisms during the change process. The implementation does not require users to provide the current password before allowing a new password to be set, creating a significant security weakness in the authentication flow. This design flaw falls under the category of improper authentication handling as defined by CWE-287, which addresses authentication mechanisms that do not properly verify user credentials. The vulnerability essentially allows any authenticated user or attacker with access to the web interface to change administrative passwords without knowing the existing credentials, fundamentally undermining the security model of the device.
The operational impact of this vulnerability becomes particularly concerning when considered in conjunction with CVE-2019-20480, which likely represents a separate authentication bypass or privilege escalation vulnerability. This combination creates a complete attack vector where an attacker could gain administrative access to the gateway and then exploit the password change function to maintain persistent access. The attack chain typically involves initial access through the primary vulnerability, followed by password modification to establish long-term control. This scenario aligns with ATT&CK technique T1078.004, which covers legitimate credentials gained through exploitation of remote services. The gateway's role as a central hub for IoT communications means that successful exploitation could provide attackers with access to all connected smart devices, potentially enabling further reconnaissance and lateral movement within the network. Network segmentation and device isolation become critical defensive measures when considering the potential scope of compromise.
The security implications extend beyond simple unauthorized access, as this vulnerability could enable attackers to modify gateway configurations, intercept communications between connected devices, or even manipulate the behavior of smart appliances. The lack of proper password verification creates a backdoor that could be exploited for extended periods without detection, making it particularly dangerous for environments where the gateway serves as a primary network control point. Organizations and individuals relying on such devices should implement immediate mitigations including firmware updates to version 2.4.0 or later, network monitoring for unusual authentication patterns, and consideration of network segmentation to limit the potential impact of compromise. The vulnerability demonstrates the importance of proper authentication design and the necessity of implementing multi-factor authentication mechanisms for critical network infrastructure devices. This flaw also highlights the need for comprehensive security testing of IoT devices, particularly those handling authentication and access control functions, as the consequences of such vulnerabilities can extend far beyond the immediate device scope into broader network security concerns.