CVE-2016-5649 in DGN2200
Summary
by MITRE
A vulnerability is in the 'BSW_cxttongr.htm' page of the Netgear DGN2200, version DGN2200-V1.0.0.50_7.0.50, and DGND3700, version DGND3700-V1.0.0.17_1.0.17, which can allow a remote attacker to access this page without any authentication. When processed, it exposes the admin password in clear text before it gets redirected to absw_vfysucc.cgia. An attacker can use this password to gain administrator access to the targeted router's web interface.
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Analysis
by VulDB Data Team • 06/25/2020
The vulnerability identified as CVE-2016-5649 affects Netgear DGN2200 and DGND3700 router models, representing a critical authentication bypass flaw that compromises the security posture of network infrastructure devices. This vulnerability exists within the BSW_cxttongr.htm web page component of the affected firmware versions, specifically DGN2200-V1.0.0.50_7.0.50 and DGND3700-V1.0.0.17_1.0.17. The flaw stems from improper access controls that fail to enforce authentication requirements for sensitive administrative pages, creating an unauthorized entry point for malicious actors. This type of vulnerability falls under CWE-285, which addresses improper authorization issues in software systems, and aligns with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting through social engineering or direct access methods.
The technical implementation of this vulnerability allows remote attackers to directly access administrative functions without providing any credentials, effectively eliminating the need for authentication mechanisms that should normally protect sensitive router configuration interfaces. When the vulnerable page is accessed, it processes the request and inadvertently displays the administrator password in plaintext format before redirecting users to the absw_vfysucc.cgia page. This plaintext exposure represents a severe security weakness as it provides attackers with immediate access credentials that can be used to gain full administrative control over the affected devices. The vulnerability demonstrates a clear failure in input validation and access control implementation, where the system does not properly verify user authorization status before displaying sensitive information.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables complete compromise of the affected router's administrative interface. Once an attacker obtains the administrator password, they can modify network configurations, change DNS settings, implement malicious routing rules, or establish backdoor access points that persist even after device reboots. The exposure of administrative credentials through a simple web page access means that attackers can exploit this vulnerability from anywhere on the internet without requiring physical access or specialized tools. This vulnerability particularly affects enterprise and home network environments where router security is often overlooked, creating potential for widespread network disruption, data exfiltration, or lateral movement within compromised networks. The vulnerability's remote exploitability makes it especially dangerous as it can be leveraged by attackers without the need for insider knowledge or physical presence at the target location.
Mitigation strategies for CVE-2016-5649 should prioritize immediate firmware updates from Netgear to address the authentication bypass flaw and prevent exploitation. Network administrators should implement network segmentation to isolate critical devices and limit potential lateral movement if a device becomes compromised. Additional security measures include disabling unnecessary web interfaces, implementing strong access controls for router management, and monitoring network traffic for suspicious activity related to router management ports. Organizations should also consider implementing network access control policies that restrict administrative access to trusted networks and devices. The vulnerability highlights the importance of proper authentication implementation and the need for regular security assessments of network infrastructure devices to identify and remediate similar access control weaknesses. Regular firmware updates and security audits should be part of routine network maintenance to prevent exploitation of known vulnerabilities that could lead to complete network compromise.