CVE-2011-4497 in Rt-n56u
Summary
by MITRE
QIS_wizard.htm on the ASUS RT-N56U router with firmware before 1.0.1.4o allows remote attackers to obtain the administrator password via a flag=detect request.
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Analysis
by VulDB Data Team • 04/23/2025
The vulnerability identified as CVE-2011-4497 affects the ASUS RT-N56U router firmware version 1.0.1.4o and earlier, presenting a critical security risk through an insecure configuration in the web interface. This flaw exists within the QIS_wizard.htm component which handles the quick installation wizard functionality, allowing unauthorized remote attackers to extract administrative credentials through a specific request parameter. The vulnerability stems from insufficient input validation and improper access controls within the router's web management interface, creating an avenue for credential disclosure that directly compromises the device's security posture.
The technical implementation of this vulnerability involves a simple HTTP request with a flag=detect parameter that triggers an unintended response containing the administrator password. This represents a classic case of insecure direct object reference vulnerability where the router fails to properly authenticate or authorize access to sensitive information. The flaw operates at the application layer and demonstrates poor input sanitization practices, as the system does not validate the request parameters before processing them. According to CWE classification, this vulnerability aligns with CWE-284 Access Control Issues, specifically involving insufficient access control mechanisms that allow unauthorized users to access privileged information.
The operational impact of this vulnerability is severe as it provides remote attackers with immediate administrative access to the router configuration interface. Once obtained, the administrator password enables full control over the device including configuration changes, firmware updates, network settings modifications, and potential access to connected devices on the local network. This creates a persistent threat vector that can be exploited without requiring physical access or prior authentication credentials. The vulnerability is particularly dangerous because it affects the router's core administrative functions and can be exploited over the internet, making it an attractive target for automated attacks.
This vulnerability also relates to several ATT&CK framework techniques including T1078 Valid Accounts for maintaining persistent access and T1566 Phishing for Initial Access, though the primary threat vector is through network-based exploitation rather than social engineering. The attack surface is significantly expanded by the fact that this vulnerability affects the web-based management interface, which is typically exposed to external networks for remote administration purposes. Organizations using affected router models face immediate risk of network compromise, potential data exfiltration, and the possibility of these devices being used as entry points for further attacks within the network infrastructure.
Mitigation strategies for CVE-2011-4497 include immediate firmware updates to version 1.0.1.4o or later, which ASUS released to address this specific vulnerability. Network administrators should also implement additional security measures such as restricting external access to router management interfaces, changing default administrative passwords, and implementing network segmentation to limit the impact of potential compromise. Regular security audits of network infrastructure should include verification of firmware versions and patch management processes to prevent similar vulnerabilities from being exploited. The vulnerability highlights the importance of proper input validation and access control implementation in embedded systems and web applications, serving as a reminder that even seemingly minor interface components can create significant security risks when not properly secured.