CVE-2017-14419 in DIR-850L
Summary
by MITRE
The D-Link NPAPI extension, as used on D-Link DIR-850L REV. A (with firmware through FW114WWb07_h2ab_beta1) and REV. B (with firmware through FW208WWb02) devices, participates in mydlink Cloud Services by establishing a TCP relay service for HTTP, even though a TCP relay service for HTTPS is also established.
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Analysis
by VulDB Data Team • 11/15/2019
The vulnerability described in CVE-2017-14419 represents a significant security flaw in D-Link's cloud service implementation on their DIR-850L router models. This issue specifically affects devices running firmware versions up to FW114WWb07_h2ab_beta1 for revision A and FW208WWb02 for revision B. The core problem lies in the D-Link Network Processing API (NPAPI) extension that facilitates communication with mydlink Cloud Services, creating an inconsistent security posture that exposes users to potential man-in-the-middle attacks and unauthorized data interception.
The technical flaw manifests through the improper implementation of TCP relay services within the NPAPI extension. While the system correctly establishes a TCP relay service for HTTPS traffic, it simultaneously creates an insecure TCP relay service for HTTP traffic without proper authentication or encryption mechanisms. This dual service approach creates a dangerous attack surface where HTTP traffic can be intercepted and manipulated by malicious actors. The vulnerability stems from a lack of proper protocol differentiation and security controls within the cloud service integration, allowing unencrypted HTTP communication to coexist with encrypted HTTPS connections.
This configuration creates multiple operational impacts that extend beyond simple data exposure. The presence of unencrypted HTTP relay services means that sensitive information transmitted between the router and mydlink cloud services can be intercepted, modified, or redirected by attackers. The vulnerability particularly affects users who rely on D-Link's cloud services for remote access and device management, as it undermines the security of all HTTP communications. Attackers could potentially exploit this weakness to capture login credentials, manipulate device configurations, or redirect traffic to malicious endpoints, fundamentally compromising the security of the home network.
From a cybersecurity perspective, this vulnerability aligns with CWE-319 (CWE-319: Cleartext Transmission of Sensitive Information) and represents a classic case of inadequate transport layer security implementation. The issue also maps to ATT&CK technique T1071.004 (Application Layer Protocol: DNS) and T1046 (Network Service Scanning) as attackers could leverage the exposed HTTP relay service to discover network services and potentially escalate privileges. Organizations and individuals should immediately update their firmware to versions that address this inconsistency in TCP relay service implementation. The mitigation strategy requires firmware updates from D-Link that properly disable or secure the HTTP relay service, ensuring that only encrypted HTTPS connections are established for cloud communications. Additionally, network administrators should implement firewall rules to block unauthorized access to the affected TCP relay ports and monitor for suspicious network activity that might indicate exploitation attempts.