CVE-2018-20387 in BCW700J
Summary
by MITRE
Bnmux BCW700J 5.20.7, BCW710J 5.30.6a, and BCW710J2 5.30.16 devices allow remote attackers to discover credentials via iso.3.6.1.4.1.4491.2.4.1.1.6.1.1.0 and iso.3.6.1.4.1.4491.2.4.1.1.6.1.2.0 SNMP requests.
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Analysis
by VulDB Data Team • 04/23/2020
The vulnerability identified as CVE-2018-20387 affects Bnmux BCW700J, BCW710J, and BCW710J2 network devices running specific firmware versions. This issue represents a critical security flaw that exposes sensitive authentication credentials through improperly configured Simple Network Management Protocol implementations. The affected devices utilize SNMP (Simple Network Management Protocol) to communicate network management information, but fail to properly secure sensitive data within their SNMP response mechanisms.
The technical flaw manifests through specific SNMP object identifiers that reveal credential information when accessed by unauthorized remote attackers. The vulnerable OID paths iso.3.6.1.4.1.4491.2.4.1.1.6.1.1.0 and iso.3.6.1.4.1.4491.2.4.1.1.6.1.2.0 contain sensitive information that should remain protected but are accessible through standard SNMP queries. This represents a direct violation of information disclosure principles and falls under CWE-200, which addresses the exposure of sensitive information to unauthorized actors. The vulnerability allows attackers to obtain authentication credentials without requiring prior access to the device or knowledge of valid credentials, making it particularly dangerous for network infrastructure devices.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables attackers to gain unauthorized access to network management functions and potentially compromise entire network infrastructures. Network administrators who rely on these devices for monitoring and management purposes face significant risk of unauthorized access to their network resources. The vulnerability affects devices that are commonly deployed in enterprise and industrial environments where network security is paramount, making the potential for widespread impact considerable. Attackers can leverage this weakness to escalate privileges, modify network configurations, or establish persistent access points within the network infrastructure.
Mitigation strategies should focus on immediate network segmentation and access control measures to prevent unauthorized SNMP access. Organizations should implement proper SNMPv3 configurations with strong authentication and encryption mechanisms, as SNMPv1 and SNMPv2c are inherently insecure and vulnerable to this type of attack. Network administrators must disable unnecessary SNMP services and restrict SNMP access to authorized management stations only. Additionally, implementing network monitoring solutions that can detect anomalous SNMP traffic patterns will help identify potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1078 Valid Accounts, as it enables attackers to obtain legitimate network credentials through legitimate network management protocols. Regular firmware updates should be implemented to address the underlying software flaw, while network administrators should conduct comprehensive vulnerability assessments to identify other potentially exposed devices within their infrastructure that may be similarly affected by improper SNMP configuration practices.