CVE-2013-20003 in Z-Wave
Summary
by MITRE • 02/05/2022
Z-Wave devices from Sierra Designs (circa 2013) and Silicon Labs (using S0 security) may use a known, shared network key of all zeros, allowing an attacker within radio range to spoof Z-Wave traffic.
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Analysis
by VulDB Data Team • 02/07/2022
The vulnerability identified as CVE-2013-20003 represents a critical security flaw in Z-Wave wireless communication systems that affected devices manufactured by Sierra Designs around 2013 and those utilizing Silicon Labs S0 security protocols. This weakness stems from the improper implementation of cryptographic security measures within the Z-Wave network infrastructure, specifically in how network keys are configured and managed during device initialization and pairing processes. The flaw allows unauthorized parties within radio transmission range to intercept and manipulate Z-Wave traffic by exploiting a hardcoded network key value of all zeros, which was intended to provide a default security mechanism but instead created a significant backdoor for malicious actors.
The technical implementation of this vulnerability involves the use of a default network key that remains unchanged across multiple device deployments, creating a predictable and easily exploitable security weakness. When devices are configured with the all-zero network key, they fail to establish proper encryption for communication between nodes in the Z-Wave network, allowing attackers to perform man-in-the-middle attacks, traffic spoofing, and unauthorized device control. This flaw directly relates to CWE-798, which addresses the use of hard-coded credentials, and CWE-310, which covers cryptographic weaknesses in key management. The vulnerability is particularly concerning because Z-Wave networks are commonly deployed in residential and commercial security systems, where the compromise of a single device can potentially allow attackers to gain access to entire home or building automation networks.
The operational impact of this vulnerability extends far beyond simple network disruption, as it enables attackers to perform sophisticated attacks within the physical environment of the target premises. An attacker within radio range can not only eavesdrop on legitimate communications but can also inject malicious commands into the Z-Wave network, potentially leading to unauthorized access to locks, lighting systems, thermostats, and other connected devices. This capability directly maps to several ATT&CK techniques including T1046 for network service scanning and T1566 for credential harvesting, as the attacker can use the compromised network to establish persistent access to the physical security infrastructure. The vulnerability also enables lateral movement within the network, as compromised devices can be used as relay points to attack other connected systems, and the lack of proper authentication mechanisms means that even legitimate devices can be impersonated by attackers.
Mitigation strategies for CVE-2013-20003 require immediate attention from system administrators and security personnel responsible for Z-Wave networks. The primary remediation involves updating firmware on affected devices to ensure that network keys are properly generated and configured during the pairing process, rather than relying on default values. Organizations should implement network key rotation procedures and ensure that all devices are configured with unique, randomly generated network keys during initial setup. The implementation of network monitoring solutions can help detect anomalous traffic patterns that may indicate exploitation attempts, while physical security measures such as limiting radio transmission range and implementing additional network segmentation can reduce the attack surface. Security professionals should also consider the broader context of the Z-Wave ecosystem and ensure that other devices in the network are not similarly vulnerable to default credential issues, as this vulnerability often exists in conjunction with other security weaknesses that compound the overall risk to the network infrastructure.