CVE-2020-15342 in CloudCNM SecuManager
Summary
by MITRE • 09/29/2022
Zyxel CloudCNM SecuManager 3.1.0 and 3.1.1 has an unauthenticated zy_install_user API.
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Analysis
by VulDB Data Team • 10/25/2022
The vulnerability identified as CVE-2020-15342 affects Zyxel CloudCNM SecuManager versions 3.1.0 and 3.1.1, representing a critical security flaw that exposes administrative functionality without proper authentication requirements. This issue resides within the zy_install_user API endpoint, which serves as a mechanism for user account creation and management within the system. The absence of authentication checks on this particular API endpoint creates a significant attack surface that allows any remote unauthenticated user to potentially execute privileged operations. The vulnerability stems from improper access control implementation where the system fails to verify the identity of callers before permitting administrative actions to be performed through the API interface. This flaw directly violates fundamental security principles of authentication and authorization, creating an environment where malicious actors can exploit the system without requiring valid credentials or prior access rights. The zy_install_user API specifically handles user installation processes which typically require elevated privileges, yet the implementation does not enforce any form of authentication validation before executing these operations.
The technical impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to perform user management operations that could fundamentally alter the system's security posture. An attacker exploiting this vulnerability could potentially create new administrative accounts, modify existing user permissions, or manipulate the user database in ways that compromise the entire system. The operational implications are severe as this vulnerability affects the core administrative functionality of the SecuManager platform, potentially allowing attackers to establish persistent access or escalate privileges within the network environment. The unauthenticated nature of the API endpoint means that exploitation can occur from any network location without requiring prior knowledge of valid credentials, making this vulnerability particularly dangerous in environments where the system is exposed to external networks. This flaw essentially provides a backdoor mechanism that bypasses the normal authentication flow, allowing unauthorized entities to perform administrative functions that should only be accessible to authenticated administrators.
Security professionals should recognize this vulnerability as a clear example of inadequate access control implementation, which aligns with CWE-285 (Improper Authorization) and CWE-306 (Missing Authentication for Critical Function). The attack surface created by this vulnerability can be mapped to multiple ATT&CK techniques including T1078 (Valid Accounts) and T1566 (Phishing), as attackers can leverage the exposed API to establish unauthorized access and potentially use legitimate accounts for further exploitation. Organizations using affected Zyxel CloudCNM SecuManager versions should immediately implement mitigations including network segmentation to limit access to the affected API endpoints, applying the vendor-provided security patches, and implementing additional monitoring for unusual API access patterns. The vulnerability demonstrates the critical importance of proper authentication mechanisms in administrative interfaces and highlights the need for comprehensive security testing of all API endpoints to ensure that privileged functions are adequately protected against unauthorized access attempts.