CVE-2018-18205 in CC8800 CMTS C-E
Summary
by MITRE
Topvision CC8800 CMTS C-E devices allow remote attackers to obtain sensitive information via a direct request for /WebContent/startup.tar.gz with userName=admin in a cookie.
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Analysis
by VulDB Data Team • 08/01/2023
The CVE-2018-18205 vulnerability affects Topvision CC8800 CMTS C-E devices, representing a critical information disclosure flaw that enables remote attackers to access sensitive system data without authentication. This vulnerability resides within the web interface of the device and specifically targets the handling of cookie-based authentication mechanisms. The flaw manifests when an attacker sends a direct HTTP request to the /WebContent/startup.tar.gz endpoint while including a cookie with userName=admin, bypassing normal authentication procedures and gaining unauthorized access to critical system files.
The technical implementation of this vulnerability stems from improper access control mechanisms within the device's web server implementation. The system fails to properly validate authentication state when processing requests for the startup.tar.gz file, which contains system configuration data, firmware components, and potentially sensitive operational parameters. This represents a classic case of insufficient authorization checks where the device assumes that any request to the specific endpoint can be served without proper authentication validation. The vulnerability falls under CWE-285, which addresses improper authorization issues, and demonstrates how weak session management can lead to complete system compromise. The use of a hardcoded admin username in the cookie parameter suggests a design flaw in the authentication token generation or validation process.
The operational impact of this vulnerability is severe as it provides attackers with access to sensitive system information that could be leveraged for further exploitation. The startup.tar.gz file typically contains firmware images, configuration files, and system binaries that could reveal system architecture, software versions, and potential weaknesses in the device's implementation. This information disclosure could enable attackers to conduct targeted attacks against known vulnerabilities in the firmware or to develop more sophisticated exploitation techniques. The remote nature of the attack means that adversaries can exploit this flaw from outside the network perimeter without requiring physical access or prior credentials. This vulnerability aligns with ATT&CK technique T1083 (File and Directory Discovery) and T1592 (Gather Victim Host Information) as it enables unauthorized access to system files and information gathering.
Organizations utilizing Topvision CC8800 CMTS C-E devices should immediately implement mitigations including disabling unnecessary web interfaces, implementing network segmentation to restrict access to these devices, and applying vendor-provided firmware updates. The vulnerability highlights the importance of proper authentication validation and access control implementation in network infrastructure devices. Network administrators should consider implementing web application firewalls to monitor and block suspicious requests to sensitive endpoints. Regular security assessments of network infrastructure devices should include testing for similar information disclosure vulnerabilities. The incident underscores the critical need for secure coding practices and proper input validation in embedded systems, particularly in telecommunications equipment where unauthorized access can compromise entire network operations. This vulnerability serves as a reminder of the importance of following security best practices such as the principle of least privilege and implementing robust authentication mechanisms in all network-accessible components.