CVE-2006-2561 in Br 6104k
Summary
by MITRE
Edimax BR-6104K router allows remote attackers to bypass access restrictions and conduct unauthorized operations via a UPnP request with a modified InternalClient parameter (possibly within NewInternalClient), which is not validated, as demonstrated by using AddPortMapping to forward arbitrary traffic.
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Analysis
by VulDB Data Team • 09/10/2017
The Edimax BR-6104K router vulnerability represents a critical access control flaw that undermines the security posture of network infrastructure devices. This vulnerability resides in the Universal Plug and Play implementation within the router's firmware, specifically in how it processes UPnP requests. The flaw allows remote attackers to manipulate the InternalClient parameter within UPnP messages, particularly when using the AddPortMapping function, thereby bypassing intended access restrictions and gaining unauthorized control over network traffic routing. The vulnerability stems from inadequate input validation mechanisms that fail to properly sanitize or verify the authenticity of parameters submitted through UPnP protocols.
The technical exploitation of this vulnerability occurs through the manipulation of UPnP requests where attackers can modify the InternalClient parameter to specify arbitrary internal IP addresses or ports. This modification enables unauthorized port mapping operations that can redirect network traffic to unintended destinations. The flaw is particularly dangerous because it allows attackers to perform actions that should be restricted to authorized users or internal network components, effectively creating backdoors for traffic redirection and potentially enabling further attack vectors such as port scanning or service enumeration. The vulnerability operates at the network layer where UPnP is typically used for automatic port configuration, making it a prime target for attackers seeking to establish persistent network access.
From an operational impact perspective, this vulnerability compromises the fundamental security model of the router by allowing remote attackers to modify network routing rules without proper authentication or authorization. Network administrators may lose visibility into their network traffic patterns as attackers can silently redirect traffic through port mappings they create. The implications extend beyond simple traffic redirection to include potential data exfiltration, service disruption, and the establishment of persistent access points within the network. This vulnerability particularly affects enterprise and home networks where the router serves as the primary gateway, making it a valuable target for attackers seeking to establish footholds within larger network infrastructures. The attack can be executed remotely without requiring physical access or prior authentication credentials, significantly increasing the attack surface and reducing the time required for exploitation.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and parameter sanitization within UPnP implementations. Network administrators should disable UPnP functionality on routers when it is not required for network operations, as this eliminates the attack vector entirely. Additionally, implementing network segmentation and access control lists can help limit the impact of successful exploitation by restricting lateral movement within the network. The vulnerability aligns with CWE-20, which addresses improper input validation, and represents a clear violation of the principle of least privilege in network security. From an ATT&CK framework perspective, this vulnerability maps to techniques involving port mapping and network infiltration, potentially enabling later stages of attack such as privilege escalation or data collection. Regular firmware updates and security audits should be implemented to address similar vulnerabilities in network infrastructure devices, as this flaw demonstrates the importance of validating all external inputs in network services. Organizations should also consider implementing network monitoring solutions that can detect anomalous port mapping activities that may indicate exploitation attempts.