CVE-2013-3366 in TEW-812DRU
Summary
by MITRE
Undocumented TELNET service in TRENDnet TEW-812DRU when a web page named backdoor contains an HTML parameter of password and a value of j78G�DFdg_24Mhw3.
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Analysis
by VulDB Data Team • 02/13/2024
The CVE-2013-3366 vulnerability represents a critical backdoor access point discovered in TRENDnet TEW-812DRU wireless routers, exposing a significant security flaw in network infrastructure devices. This vulnerability stems from an undocumented telnet service that operates on the affected router model, creating an unauthorized access vector that bypasses normal authentication mechanisms. The backdoor is activated through a specific web page payload containing a password parameter with the value j78G�DFdg_24Mhw3, which serves as a hardcoded credential for unauthorized remote access. This flaw demonstrates poor security practices in embedded device development where default credentials and undocumented services are improperly configured, creating persistent attack surfaces that remain undetected by standard security scanning tools.
The technical implementation of this vulnerability involves a combination of web-based exploitation and network service manipulation that allows attackers to gain root-level access to the router's operating system. The presence of the undocumented telnet service indicates a lack of proper access control mechanisms and insufficient security hardening of the device firmware. When the specific HTML parameter is accessed through a web interface, the router's firmware interprets this as a valid authentication request, automatically granting administrative privileges without proper user verification. This vulnerability aligns with CWE-255 - Credentials Management Issues and CWE-79 - Improper Neutralization of Input During Web Page Generation, as it involves both improper credential handling and insecure web application design patterns. The attack vector operates through web-based exploitation techniques that fall under ATT&CK technique T1190 - Exploit Public-Facing Application, demonstrating how insecure web interfaces can serve as entry points for network compromise.
The operational impact of CVE-2013-3366 extends beyond simple unauthorized access to encompass full network compromise and persistent backdoor capabilities. Once an attacker gains access through this vulnerability, they can manipulate router configurations, redirect network traffic, monitor communications, and establish additional persistence mechanisms within the network infrastructure. The vulnerability's persistence is particularly concerning as it remains active until the device firmware is updated or the backdoor service is manually disabled, providing attackers with long-term access to the network environment. This type of vulnerability is classified as a persistent threat vector that can enable advanced persistent threat (APT) activities, where attackers can use the compromised router as a foothold for lateral movement throughout the network. The security implications are further compounded by the fact that such vulnerabilities often remain undetected for extended periods, as they do not generate typical network traffic patterns that would trigger intrusion detection systems.
Mitigation strategies for CVE-2013-3366 require immediate firmware updates from TRENDnet to address the documented backdoor implementation, though many affected devices may no longer receive official support due to their age and the time elapsed since the vulnerability disclosure. Network administrators should implement network segmentation and access control measures to limit the impact of potential compromise, while also deploying network monitoring solutions that can detect anomalous telnet traffic patterns. The vulnerability highlights the importance of firmware security testing and proper device hardening procedures, including disabling unused services and removing default credentials from network equipment. Organizations should conduct comprehensive inventory assessments to identify all affected devices and implement network access controls that prevent unauthorized access to critical infrastructure components. Security best practices recommend regular firmware updates, proper network monitoring, and adherence to security standards such as NIST SP 800-40 and ISO 27001 to prevent similar vulnerabilities from being introduced into network infrastructure components.