CVE-2018-20384 in IB-8120-W21
Summary
by MITRE
iNovo Broadband IB-8120-W21 139.4410mp1.004200.002 and IB-8120-W21E1 139.4410mp1.3921132mp1.899.004404.004 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
This vulnerability affects iNovo Broadband IB-8120-W21 and IB-8120-W21E1 wireless routers running specific firmware versions, exposing sensitive authentication credentials through improper SNMP implementation. The flaw resides in the Simple Network Management Protocol configuration where the device reveals administrative credentials through specific SNMP object identifiers. Attackers can exploit this by sending crafted SNMP GET requests to the 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 MIB paths, which correspond to the router's administrative username and password respectively. This represents a critical security weakness that violates the principle of least privilege and demonstrates poor access control implementation.
The technical exploitation of this vulnerability enables remote attackers to gain unauthorized access to the device's administrative interface without requiring any prior authentication or credentials. The SNMP implementation fails to properly restrict access to sensitive information, allowing attackers to extract credentials through simple network requests. This flaw directly maps to CWE-200 (Information Exposure) and CWE-798 (Use of Hard-coded Credentials) categories, as it exposes hardcoded or easily obtainable administrative credentials. The vulnerability exists at the network protocol level and requires no specialized tools beyond standard SNMP enumeration utilities, making it particularly dangerous for unpatched devices in production environments.
The operational impact of this vulnerability extends beyond simple credential theft, as it provides attackers with complete administrative control over the affected routers. Once credentials are obtained, attackers can modify network configurations, implement man-in-the-middle attacks, redirect traffic, or establish persistent backdoors within the network infrastructure. This represents a significant threat to network security posture and can enable lateral movement attacks within enterprise environments where these devices may serve as entry points. The vulnerability affects both the IB-8120-W21 and IB-8120-W21E1 models, suggesting a widespread issue across multiple firmware variants that share the same SNMP implementation flaw. According to ATT&CK framework, this maps to T1071.004 (Application Layer Protocol: DNS) and T1046 (Network Service Scanning) techniques, as attackers can discover and exploit this vulnerability through network reconnaissance activities.
Mitigation strategies should include immediate firmware updates from the vendor to address the SNMP credential exposure issue. Network administrators should disable SNMP access to the device or implement strict access controls limiting SNMP queries to trusted IP addresses only. The device configuration should be reviewed to ensure that default administrative credentials are changed and that SNMP is configured with appropriate security levels. Network segmentation should be implemented to isolate these devices from critical network segments, and continuous monitoring should be deployed to detect unauthorized SNMP access attempts. Additionally, organizations should conduct vulnerability assessments to identify other network devices with similar SNMP configuration issues, as this represents a common pattern of insecure network management protocol implementations that can lead to broader compromise scenarios.