CVE-2006-2560 in WL-153 router
Summary
by MITRE
Sitecom WL-153 router firmware before 1.38 allows remote attackers to bypass access restrictions and conduct unauthorized operations via a UPnP request with a modified InternalClient parameter, which is not validated, as demonstrated by using AddPortMapping to forward arbitrary traffic.
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Analysis
by VulDB Data Team • 09/07/2017
The CVE-2006-2560 vulnerability affects Sitecom WL-153 wireless routers running firmware versions prior to 1.38, representing a critical security flaw in the Universal Plug and Play implementation. This vulnerability resides in the router's handling of UPnP requests where the InternalClient parameter is not properly validated, creating a pathway for remote attackers to bypass legitimate access controls. The flaw specifically manifests when attackers send crafted UPnP requests that modify the InternalClient field, enabling them to perform unauthorized operations within the network infrastructure. The vulnerability is particularly concerning as it allows attackers to manipulate port mapping configurations through the AddPortMapping function, which should normally be restricted to authorized internal clients.
The technical nature of this vulnerability aligns with CWE-284, which addresses improper access control in software implementations, and represents a classic case of input validation failure within network services. The flaw operates at the network protocol level where the UPnP service fails to authenticate or validate the source of requests that modify network configuration parameters. When attackers exploit this vulnerability, they can effectively bypass the router's built-in access control mechanisms and establish unauthorized port mappings that forward arbitrary traffic to internal network devices. This creates a significant attack surface where external adversaries can gain access to internal network resources without proper authentication or authorization, potentially leading to complete network compromise.
The operational impact of CVE-2006-2560 extends beyond simple unauthorized access to encompass complete network infiltration capabilities. Attackers can leverage this vulnerability to redirect traffic to malicious servers, establish backdoors, or perform reconnaissance activities on internal network segments. The ability to use AddPortMapping for arbitrary traffic forwarding means that attackers can effectively bypass firewall rules and network segmentation controls that are typically enforced by the router. This vulnerability undermines the fundamental security model of home and small office routers, which rely on proper access control to protect internal networks from external threats. The implications are particularly severe in environments where these routers serve as the primary network boundary protection, as they provide attackers with direct pathways to sensitive internal systems.
Mitigation strategies for CVE-2006-2560 should focus on immediate firmware updates to version 1.38 or later, which addresses the validation issue in the UPnP implementation. Network administrators should also implement additional protective measures such as disabling UPnP functionality entirely when it is not required, as this eliminates the attack surface associated with the vulnerable service. The implementation of network segmentation and firewall rules can provide additional layers of protection by restricting access to the affected UPnP ports and services. Organizations should also consider monitoring network traffic for unusual UPnP activity patterns that might indicate exploitation attempts, particularly around the AddPortMapping operations that are characteristic of this vulnerability. Security best practices recommend that all network devices be kept up to date with the latest security patches, as this vulnerability demonstrates the importance of proper input validation in network services. The ATT&CK framework would categorize this vulnerability under T1071.004 for application layer protocol usage and T1068 for local privilege escalation through service manipulation, highlighting the multi-faceted nature of the threat posed by unvalidated UPnP requests.