CVE-2006-3595 in Router Web Setup
Summary
by MITRE
The default configuration of IOS HTTP server in Cisco Router Web Setup (CRWS) before 3.3.0 build 31 does not require credentials, which allows remote attackers to access the server with arbitrary privilege levels, aka bug CSCsa78190.
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Analysis
by VulDB Data Team • 12/17/2024
The vulnerability described in CVE-2006-3595 represents a critical security flaw in the Cisco IOS HTTP server implementation within the Cisco Router Web Setup component. This issue affects versions prior to 3.3.0 build 31 and demonstrates a fundamental failure in authentication mechanisms that undermines the security posture of affected network devices. The vulnerability stems from the default configuration of the HTTP server which operates without requiring any form of credentials for access, creating an inherent security weakness that exposes router management interfaces to unauthorized access.
The technical flaw manifests in the absence of proper authentication controls within the HTTP server implementation. When the Cisco Router Web Setup component is installed on IOS devices, the HTTP server defaults to a configuration that permits unauthenticated access to administrative functions. This configuration allows attackers to establish connections to the HTTP server and interact with the router management interface without providing any valid credentials. The vulnerability specifically affects the authentication mechanism that should normally enforce privilege levels, instead allowing arbitrary access regardless of user credentials or roles. This design flaw creates a pathway for remote attackers to gain unauthorized access to router configuration and management functions.
The operational impact of this vulnerability is severe and far-reaching for network security. Remote attackers can exploit this weakness to gain full administrative access to affected routers, potentially leading to complete network compromise. The vulnerability allows attackers to perform any administrative function including configuration changes, firmware updates, access control modifications, and network monitoring capabilities. This unauthenticated access creates opportunities for attackers to establish persistent backdoors, redirect traffic, disable security features, or exfiltrate sensitive network information. The impact extends beyond individual device compromise to potentially affect entire network infrastructures, as routers often serve as critical network gateways and control points.
The vulnerability aligns with CWE-287 which addresses improper authentication issues in software systems, specifically highlighting the danger of insufficient authentication mechanisms. From an attack framework perspective, this vulnerability maps to ATT&CK technique T1078 which covers valid accounts and T1566 which involves credential harvesting. The lack of credential requirements creates an ideal attack vector for initial access and privilege escalation within network environments. Organizations with affected devices face significant risk of unauthorized network access, configuration tampering, and potential data breaches. The vulnerability demonstrates the critical importance of proper authentication mechanisms and default security configurations in network infrastructure devices.
Mitigation strategies for this vulnerability require immediate action to address the insecure default configuration. The primary solution involves upgrading affected Cisco IOS devices to versions 3.3.0 build 31 or later where the authentication requirements have been properly implemented. Network administrators should also implement additional security measures such as restricting HTTP server access through firewall rules, disabling the HTTP server when not required, and implementing network segmentation to limit access to management interfaces. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of the vulnerable configuration. The remediation process must include thorough testing to ensure that the updated configuration maintains necessary network functionality while providing proper authentication controls. Organizations should also establish procedures for monitoring and maintaining secure default configurations across their network infrastructure to prevent similar issues from occurring in the future.