CVE-2018-20399 in SBG901
Summary
by MITRE
Motorola SBG901 SBG901-2.10.1.1-GA-00-581-NOSH, SBG941 SBG941-2.11.0.0-GA-07-624-NOSH, and SVG1202 SVG1202-2.1.0.0-GA-14-LTSH 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 Motorola SBG901 SBG901-2.10.1.1-GA-00-581-NOSH, SBG941 SBG941-2.11.0.0-GA-07-624-NOSH, and SVG1202 SVG1202-2.1.0.0-GA-14-LTSH devices that implement SNMP protocols for network management and monitoring. The flaw resides in the SNMP implementation where specific OID requests can be used to extract sensitive credential information from the affected devices. This represents a critical security weakness that allows unauthenticated remote attackers to access system credentials without requiring any prior authentication or authorization. The vulnerability specifically impacts 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 SNMP object identifiers which are designed to provide system configuration and administrative information. The flaw falls under CWE-200 - Information Exposure, which is categorized as a weakness that allows information to be exposed to unauthorized actors. This vulnerability directly enables credential harvesting attacks and aligns with ATT&CK technique T1082 - System Information Discovery, where adversaries gather information about the target system to aid in further exploitation. The affected devices operate in residential and small office environments where they often serve as primary internet gateways, making them attractive targets for attackers seeking to establish persistent access or escalate privileges within the network. The SNMP implementation fails to properly validate or restrict access to sensitive configuration data, allowing attackers to perform simple OID queries that return administrative usernames and potentially passwords.
The operational impact of this vulnerability extends beyond simple credential theft as it provides attackers with the foundation for more sophisticated attacks within the network infrastructure. Once credentials are obtained through SNMP queries, attackers can potentially gain administrative access to the devices, allowing them to modify network configurations, redirect traffic, or establish backdoors for persistent access. The vulnerability enables a range of malicious activities including man-in-the-middle attacks, network reconnaissance, and privilege escalation. Organizations using these devices face significant risk as the exposed credentials can be used to compromise not only the individual device but potentially the entire network segment. The vulnerability affects devices that are typically deployed in environments where network security is not prioritized, making the impact more severe. This weakness creates a persistent threat vector that remains active until the device is updated or the SNMP service is properly secured. The exposure of administrative credentials through SNMP queries represents a fundamental failure in the principle of least privilege, where sensitive information is accessible through publicly known OIDs without proper authentication mechanisms.
Mitigation strategies for this vulnerability require immediate action to secure the affected devices and prevent unauthorized access. Organizations should implement SNMP access controls by configuring SNMP community strings with appropriate access levels and restricting access to trusted management stations only. The most effective immediate mitigation involves disabling SNMPv1 and SNMPv2c protocols entirely, as these versions lack proper authentication and encryption mechanisms. Device administrators should upgrade to SNMPv3 which provides authentication and encryption capabilities to protect against credential exposure. Network segmentation should be implemented to isolate affected devices from critical network segments, limiting the potential impact of credential compromise. Regular network monitoring should be deployed to detect unauthorized SNMP access attempts and unusual OID queries. Device firmware updates should be applied immediately if available from Motorola, as these vulnerabilities are typically addressed through security patches. Network administrators should also implement proper access controls for SNMP services, ensuring that only authorized personnel can query sensitive OIDs. Additionally, network scanning tools should be used to identify any devices that may be vulnerable to similar SNMP-related exposures within the organization's infrastructure. The vulnerability highlights the importance of proper SNMP configuration management and demonstrates how default configurations can create significant security risks when not properly secured. Organizations should establish security policies that mandate regular review and hardening of network device configurations, particularly for protocols that provide access to system-level information. This vulnerability serves as a reminder that even devices in consumer-grade networking equipment can present significant security risks when not properly configured and maintained.