CVE-2015-5536 in N300 Dual-Band Wi-Fi Range Extender
Summary
by MITRE
Belkin N300 Dual-Band Wi-Fi Range Extender with firmware before 1.04.10 allows remote authenticated users to execute arbitrary commands via the (1) sub_dir parameter in a formUSBStorage request; pinCode parameter in a (2) formWpsStart or (3) formiNICWpsStart request; (4) wps_enrolee_pin parameter in a formWlanSetupWPS request; or unspecified parameters in a (5) formWlanMP, (6) formBSSetSitesurvey, (7) formHwSet, or (8) formConnectionSetting request.
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Analysis
by VulDB Data Team • 10/14/2017
The CVE-2015-5536 vulnerability affects Belkin N300 Dual-Band Wi-Fi Range Extender devices running firmware versions prior to 1.04.10, representing a critical remote command execution flaw that enables authenticated attackers to gain arbitrary code execution on the affected devices. This vulnerability stems from inadequate input validation and sanitization within multiple web interface forms, creating multiple attack vectors that can be exploited by remote authenticated users who have access to the device's web management interface. The flaw manifests through several distinct parameters across different HTTP POST requests, making it particularly dangerous as attackers can leverage any of these vectors to compromise the device without requiring physical access or additional privileges beyond legitimate user authentication.
The technical exploitation occurs through improper handling of user-supplied input in various web forms, where the device fails to properly validate or sanitize parameters before processing them. The vulnerability specifically targets the sub_dir parameter in formUSBStorage requests, the pinCode parameter in WPS-related forms, and the wps_enrolee_pin parameter in formWlanSetupWPS requests, along with unspecified parameters in several other configuration forms. These parameters are directly processed by the device's web server without adequate sanitization, allowing attackers to inject malicious commands that get executed in the context of the web server process. The vulnerability maps to CWE-77 and CWE-94, which respectively cover command injection and code injection flaws, both of which are classified as high-risk vulnerabilities in the Common Weakness Enumeration catalog.
From an operational perspective, this vulnerability creates significant security implications for network infrastructure, as compromised range extenders can serve as persistent footholds for attackers to conduct further network reconnaissance, establish command and control channels, or launch attacks against other devices within the same network segment. The remote nature of the exploitation means that attackers can compromise these devices from anywhere on the internet, provided they have valid credentials to access the web interface. This vulnerability aligns with ATT&CK technique T1059, which covers command and scripting interpreters, and T1071, covering application layer protocols, as attackers can leverage the compromised device to execute malicious commands and communicate with external systems. Network administrators face particular challenges with this vulnerability since it can be exploited by legitimate users who have access to the device, making detection more difficult and potentially allowing attackers to remain undetected for extended periods.
Mitigation strategies for CVE-2015-5536 primarily involve upgrading to firmware version 1.04.10 or later, which contains patches addressing the input validation issues in the affected web forms. Organizations should also implement network segmentation to limit access to these devices, enforce strong authentication mechanisms, and regularly audit device configurations to ensure that only authorized personnel have access to management interfaces. Additional security controls such as network monitoring for unusual command execution patterns and implementing web application firewalls can provide additional layers of protection. The vulnerability demonstrates the importance of input validation in embedded web interfaces and highlights the need for regular firmware updates to address known security flaws, particularly in IoT devices that often lack robust security features and are frequently deployed in enterprise environments where they can serve as attack vectors for broader network compromises.