CVE-2004-1540 in ZyNOS
Summary
by MITRE
ZyXEL Prestige 623, 650, and 652 HW Routers, and possibly other versions, with HTTP Remote Administration enabled, does not require a password to access rpFWUpload.html, which allows remote attackers to reset the router configuration file.
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Analysis
by VulDB Data Team • 10/30/2024
The vulnerability identified as CVE-2004-1540 affects ZyXEL Prestige series routers including models 623, 650, and 652 along with potentially other variants in the hardware revision line. This represents a critical security flaw in network device management interfaces where the router's web-based administration portal lacks proper authentication mechanisms for specific configuration endpoints. The vulnerability specifically targets the rpFWUpload.html file which serves as a firmware upload interface within the router's HTTP administrative framework.
The technical implementation flaw stems from insufficient access control measures within the router's web server component. When HTTP remote administration is enabled, the system fails to enforce authentication checks for the rpFWUpload.html endpoint, creating an unauthorized access vector that allows remote attackers to manipulate router configuration files. This misconfiguration directly violates fundamental security principles of authentication and authorization, as the system provides administrative access without requiring valid credentials or authentication tokens. The vulnerability is classified under CWE-287 which addresses improper authentication issues in network services.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete router compromise. Remote attackers can leverage this flaw to reset router configuration files, potentially leading to complete loss of network configuration settings, including firewall rules, routing tables, and network access controls. This attack vector allows adversaries to disrupt network services, gain persistent access to the local network, and potentially establish backdoors for future exploitation. The vulnerability creates a pathway for attackers to perform configuration tampering that could affect network availability, integrity, and confidentiality.
Security professionals should note that this vulnerability aligns with ATT&CK technique T1072 which covers software deployment via web services and T1068 which addresses local privilege escalation through administrative access. The flaw represents a classic example of insecure direct object reference where the router's administrative interface fails to properly validate access permissions for critical configuration endpoints. Organizations should implement immediate mitigations including disabling HTTP remote administration when not required, applying firmware updates from ZyXEL if available, and implementing network segmentation to limit exposure of administrative interfaces to untrusted networks. Additionally, network monitoring should be enhanced to detect unauthorized configuration changes and access attempts to administrative endpoints.
The broader implications of this vulnerability highlight the critical importance of proper authentication implementation in network device management interfaces. This flaw demonstrates how seemingly minor configuration oversights in web server implementations can create significant security risks. The vulnerability underscores the necessity of following security best practices such as principle of least privilege, proper access control implementation, and regular security audits of network device configurations. Organizations should also consider implementing additional security controls including network access control lists, secure remote access protocols, and regular vulnerability assessments to prevent similar issues in other network infrastructure components.