CVE-2011-4506 in Tg585 Router
Summary
by MITRE
The UPnP IGD implementation on the Thomson (aka Technicolor) TG585 with firmware 7.x before 7.4.3.2 allows remote attackers to establish arbitrary port mappings by sending a UPnP AddPortMapping action in a SOAP request to the WAN interface, related to an "external forwarding" vulnerability.
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Analysis
by VulDB Data Team • 08/08/2024
The vulnerability identified as CVE-2011-4506 represents a critical security flaw in the Universal Plug and Play Internet Gateway Device implementation found in Thomson TG585 routers running firmware versions 7.x prior to 7.4.3.2. This issue falls under the category of unauthorized access and privilege escalation vulnerabilities, specifically targeting the router's management interface. The flaw enables remote attackers to manipulate the router's port forwarding configuration without requiring authentication, effectively compromising the network's security boundary. The vulnerability is particularly concerning because it affects the core functionality of the router's firewall protection mechanisms, which are designed to prevent unauthorized external access to internal network resources.
The technical exploitation of this vulnerability occurs through the manipulation of the UPnP protocol implementation within the router's firmware. Attackers can send specially crafted SOAP requests containing an AddPortMapping action to the WAN interface of the device, bypassing normal authentication mechanisms that should prevent such modifications. This flaw stems from inadequate input validation and access control checks within the UPnP IGD implementation, allowing any remote attacker to add arbitrary port mappings to the router's configuration. The vulnerability is classified as a CWE-284: Improper Access Control, which specifically addresses insufficient access control mechanisms that permit unauthorized access to resources. The attack vector is remote and requires no prior authentication, making it particularly dangerous as it can be exploited from anywhere on the internet.
The operational impact of this vulnerability extends beyond simple port mapping manipulation, as it fundamentally undermines the router's ability to protect the internal network from external threats. Once exploited, attackers can establish persistent port forwards that allow them to access internal services, potentially enabling further attacks such as remote code execution, data exfiltration, or establishment of command and control channels. The vulnerability creates a backdoor that bypasses the router's normal security policies, effectively allowing attackers to open any port they choose on the internal network. This capability directly relates to the ATT&CK framework's T1071.004: Application Layer Protocol: DNS and T1046: Network Service Scanning, as attackers can use the port mapping functionality to conduct reconnaissance and establish persistent access to internal systems. The vulnerability also impacts the principle of least privilege by allowing unauthorized modifications to network security policies.
The exploitation of this vulnerability requires minimal technical expertise and can be automated through readily available tools, making it particularly dangerous for widespread deployment. Network administrators who are unaware of the vulnerability may not detect unauthorized port mappings, as they typically appear as legitimate configurations within the router's management interface. The remediation for this vulnerability requires firmware updates to version 7.4.3.2 or later, which address the insufficient access controls in the UPnP implementation. Organizations should implement network monitoring to detect unauthorized port mappings and establish baseline configurations to identify when the router's security policies have been altered. Security best practices recommend disabling UPnP functionality when not required, as it provides an additional attack surface that can be exploited by threat actors. The vulnerability also highlights the importance of secure firmware development practices and regular security assessments of network infrastructure components to prevent similar issues from occurring in other devices and implementations.