CVE-2014-4862 in Netmaster CBW700N
Summary
by MITRE
The Netmaster CBW700N cable modem with software 81.447.392110.729.024 has an SNMP community of public, which allows remote attackers to obtain sensitive credential, key, and SSID information via an SNMP request.
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Analysis
by VulDB Data Team • 08/22/2024
The Netmaster CBW700N cable modem represents a significant security vulnerability through its default SNMP community string configuration, which exposes critical network information to unauthorized remote actors. This device operates with the well-known and widely exploited SNMP community string "public" which serves as a default authentication mechanism for network management protocols. The vulnerability stems from the device's failure to implement proper access controls and authentication mechanisms, allowing any remote attacker who can reach the device's SNMP port to perform unauthorized queries against the system's management interface.
The technical flaw manifests through the insecure default configuration where the SNMP community string remains unchanged from its factory default setting. This configuration enables attackers to execute SNMP GET requests against the device, potentially retrieving sensitive information including network credentials, encryption keys, and SSID configurations. The vulnerability specifically affects software version 81.447.392110.729.024 of the CBW700N modem, indicating a widespread issue within this particular firmware release that has likely been present for an extended period. The flaw exists at the network management layer where SNMP protocol implementation fails to enforce proper authorization controls, making it a classic example of weak authentication and default credential issues.
The operational impact of this vulnerability extends beyond simple information disclosure, creating a substantial risk to network security and integrity. Remote attackers can leverage this weakness to gain comprehensive knowledge of the wireless network configuration, potentially enabling further attacks such as unauthorized network access, man-in-the-middle attacks, or credential harvesting for lateral movement within the network. The exposure of SSID information allows attackers to identify specific network targets, while the retrieval of encryption keys could compromise the entire wireless security infrastructure. This vulnerability directly impacts the confidentiality and integrity aspects of the CIA triad, as it provides unauthorized access to information that should remain protected within the network's management domain.
The vulnerability aligns with CWE-798, which addresses the use of hard-coded credentials, and CWE-255, which covers issues related to authentication mechanisms. From an ATT&CK framework perspective, this vulnerability maps to T1046 for network service scanning and T1071 for application layer protocols, while also supporting T1082 for system information discovery and T1566 for credential access through network services. Organizations utilizing this modem are particularly vulnerable to reconnaissance activities and automated exploitation tools that specifically target default SNMP community strings. The attack surface is further expanded due to the device's typical placement in network perimeters where it may be directly accessible from external networks without proper firewall restrictions.
Effective mitigations for this vulnerability require immediate implementation of several security controls. The primary remediation involves changing the default SNMP community string to a strong, randomly generated value that is not publicly known or easily guessable. Network administrators should disable SNMPv1 and SNMPv2c if possible, and migrate to SNMPv3 which provides stronger authentication and encryption mechanisms. Additional measures include implementing network segmentation to isolate the modem from critical network segments, configuring proper firewall rules to restrict access to the SNMP port, and conducting regular vulnerability assessments to identify similar insecure configurations. The device should also be updated to the latest firmware version if available, though this particular vulnerability may persist across multiple firmware versions. Regular network monitoring for unauthorized SNMP access attempts should be implemented as part of ongoing security operations to detect potential exploitation attempts.