CVE-2020-15337 in CloudCNM SecuManager
Summary
by MITRE • 09/29/2022
Zyxel CloudCNM SecuManager 3.1.0 and 3.1.1 has a "Use of GET Request Method With Sensitive Query Strings" issue for /registerCpe requests.
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Analysis
by VulDB Data Team • 10/25/2022
The vulnerability identified as CVE-2020-15337 affects Zyxel CloudCNM SecuManager versions 3.1.0 and 3.1.1, presenting a critical security flaw in how sensitive information is transmitted through HTTP requests. This issue specifically manifests in the /registerCpe endpoint where the application employs the GET request method to handle sensitive query parameters, creating a significant exposure risk that aligns with CWE-542 - Information Exposure Through Web Server Metafiles and CWE-200 - Information Exposure. The use of GET requests for transmitting sensitive data violates fundamental security principles as these parameters become visible in web server logs, browser history, and referral headers, making them accessible to unauthorized parties.
The technical flaw stems from the application's improper handling of authentication and registration parameters within HTTP GET requests. When a client system attempts to register with the SecuManager through the /registerCpe endpoint, sensitive information including potentially authentication tokens, device identifiers, and configuration parameters are passed as query string parameters in the URL. This design choice directly contravenes security best practices outlined in the OWASP Top Ten 2017 and the NIST Cybersecurity Framework, particularly in the areas of secure communication and data protection. The GET method inherently exposes these parameters in the URL, which means they are logged in web server access logs, cached by browsers, and transmitted in the Referer header when navigating between pages, creating multiple attack vectors for information disclosure.
The operational impact of this vulnerability is severe and multifaceted, as it enables attackers to obtain sensitive information that could be leveraged for further exploitation. An attacker who intercepts network traffic or gains access to web server logs can extract authentication tokens, device identifiers, and other confidential data from the URLs, potentially allowing unauthorized access to the SecuManager system. This vulnerability directly maps to ATT&CK technique T1071.004 - Application Layer Protocol: DNS, where attackers might use information gathered from such exposure to craft more sophisticated attacks. The exposure of registration parameters could enable privilege escalation, unauthorized device registration, or even complete system compromise if the exposed information includes administrative credentials or session tokens.
Mitigation strategies for this vulnerability should address both immediate remediation and long-term architectural improvements. The primary fix involves modifying the application to use POST requests instead of GET requests for the /registerCpe endpoint, ensuring that sensitive parameters are transmitted in the request body rather than the URL. This approach aligns with the principle of least privilege and follows the security guidelines established in the ISO/IEC 27001 standard for information security management. Organizations should also implement comprehensive logging and monitoring of all API endpoints to detect unusual access patterns and potential exploitation attempts. Network segmentation and access controls should be strengthened to limit exposure of the SecuManager system to trusted networks only. Additionally, regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other endpoints, as this flaw represents a broader pattern of insecure data transmission practices that may exist elsewhere in the application architecture.