CVE-2018-20439 in DPC3928SL
Summary
by MITRE
Technicolor DPC3928SL D3928SL-PSIP-13-A010-c3420r55105-170214a devices allow remote attackers to discover Wi-Fi credentials via iso.3.6.1.4.1.4413.2.2.2.1.5.4.1.14.1.3.10001 and 1.3.6.1.4.1.4413.2.2.2.1.18.1.2.3.4.1.2.10001 SNMP requests.
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Analysis
by VulDB Data Team • 04/24/2020
The vulnerability CVE-2018-20439 affects Technicolor DPC3928SL D3928SL-PSIP-13-A010-c3420r55105-170214a devices, representing a critical security flaw in network infrastructure equipment. This issue stems from improper access control mechanisms within the device's Simple Network Management Protocol implementation, specifically exposing sensitive wireless configuration parameters through unauthenticated SNMP queries. The vulnerability allows remote attackers to extract Wi-Fi credentials without requiring any authentication or prior access to the device, creating a significant risk for network security and confidentiality.
The technical flaw manifests through specific SNMP object identifiers that reveal Wi-Fi network configuration details. The affected OIDs iso.3.6.1.4.1.4413.2.2.2.1.5.4.1.14.1.3.10001 and 1.3.6.1.4.1.4413.2.2.2.1.18.1.2.3.4.1.2.10001 contain sensitive information including wireless network keys and configuration parameters. These SNMP MIBs (Management Information Bases) are accessible without proper authentication mechanisms, allowing attackers to perform simple GET requests against the device's SNMP service and retrieve the credentials. This represents a classic CWE-284 access control vulnerability where insufficient authorization checks permit unauthorized data disclosure.
The operational impact of this vulnerability extends beyond simple credential theft, creating a comprehensive security risk for enterprise and residential networks. Remote attackers can leverage this vulnerability to gain complete control over wireless network access, potentially leading to man-in-the-middle attacks, unauthorized network access, and data interception. The vulnerability affects devices deployed in both consumer and enterprise environments, making it particularly dangerous as it can be exploited from anywhere on the internet without requiring physical access or network proximity. This flaw directly violates security principles outlined in the NIST Cybersecurity Framework and represents a critical weakness in the device's security posture.
Organizations should implement immediate mitigations including disabling SNMP services when not required, implementing proper network segmentation, and applying firmware updates from Technicolor if available. Network administrators should consider deploying SNMP access control lists to restrict queries to authorized management stations only, while also implementing network monitoring to detect unauthorized SNMP traffic patterns. The vulnerability demonstrates the importance of secure configuration management and proper access control implementation as outlined in MITRE ATT&CK framework's privilege escalation and credential access tactics. Additionally, regular security assessments and vulnerability scanning should be conducted to identify similar issues in other network infrastructure devices within the organization's attack surface.