CVE-2016-4521 in BT-5xxx M2M
Summary
by MITRE
Sixnet BT-5xxx and BT-6xxx M2M devices before 3.8.21 and 3.9.x before 3.9.8 have hardcoded credentials, which allows remote attackers to obtain access via unspecified vectors.
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Analysis
by VulDB Data Team • 12/22/2018
The Sixnet BT-5xxx and BT-6xxx machine-to-machine communication devices represent a class of industrial IoT products designed for remote monitoring and control applications in various sectors including energy, utilities, and manufacturing. These devices operate within critical infrastructure environments where secure communication protocols are paramount for maintaining operational integrity and preventing unauthorized access. The vulnerability identified in CVE-2016-4521 specifically targets the authentication mechanisms of these devices, creating a significant security risk that extends beyond typical consumer IoT concerns due to the industrial nature of their deployment and the potential for cascading failures in connected systems.
The technical flaw manifests through the presence of hardcoded credentials within the device firmware, a practice that violates fundamental security principles and creates persistent access vectors for malicious actors. This vulnerability falls under the CWE-798 category of Using Hardcoded Credentials, which is classified as a high-severity weakness in the Common Weakness Enumeration system. The hardcoded credentials allow attackers to gain unauthorized access to the devices without requiring knowledge of legitimate user credentials or successful exploitation of other attack vectors. The unspecified nature of the attack vectors suggests that the vulnerability may be exploitable through multiple pathways including network-based attacks, physical access scenarios, or through compromised network segments where the devices operate.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as these M2M devices typically operate within critical infrastructure environments where they control or monitor essential services. The ability to remotely access these devices creates opportunities for attackers to manipulate industrial processes, disrupt operations, or gain access to sensitive operational data. This vulnerability particularly concerns industrial control systems and SCADA networks where the BT-5xxx and BT-6xxx devices may be integrated into larger network architectures. The lack of proper credential management and the presence of hardcoded authentication information creates a persistent threat that remains viable even after device reboots or normal operational cycles.
Security practitioners should consider this vulnerability in the context of the MITRE ATT&CK framework, specifically under the T1078 technique for Valid Accounts, where adversaries leverage default or hardcoded credentials to establish persistent access to systems. The vulnerability also aligns with T1110, which covers credential access and the exploitation of weak or default credentials. Organizations operating these devices should implement immediate remediation measures including firmware updates to versions 3.8.21 and 3.9.8 or later, which address the hardcoded credential issue. Additionally, network segmentation strategies should be employed to isolate these devices from critical network segments, and continuous monitoring should be implemented to detect unauthorized access attempts or anomalous behavior patterns that may indicate exploitation of this vulnerability. The incident highlights the importance of secure development practices and regular security assessments for industrial IoT devices to prevent similar vulnerabilities from emerging in future deployments.