CVE-2021-47709 in Smart Home Ruvie CCTV Bridge DVR Service
Summary
by MITRE • 12/10/2025
COMMAX Smart Home System allows an unauthenticated attacker to change configuration and cause denial-of-service through the setconf endpoint. Attackers can trigger a denial-of-service scenario by sending a malformed request to the setconf endpoint.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/10/2025
The COMMAX Smart Home System presents a critical security vulnerability through its setconf endpoint that lacks proper authentication mechanisms, creating a significant attack surface for unauthenticated adversaries. This vulnerability falls under the category of insufficient authentication, which is classified as CWE-287 in the Common Weakness Enumeration framework, representing a fundamental flaw in access control implementation. The system's failure to validate user credentials before permitting configuration changes creates an opportunity for malicious actors to exploit this weakness and gain unauthorized control over critical system parameters.
The technical exploitation of this vulnerability involves sending malformed requests to the setconf endpoint, which triggers a denial-of-service condition within the smart home system. This endpoint serves as a critical configuration interface that should require proper authentication and authorization before allowing any modifications to system parameters. The lack of input validation and authentication checks means that any attacker with network access can craft malicious payloads that disrupt normal system operations, potentially causing complete service interruption. The vulnerability demonstrates a classic case of insecure direct object reference and improper access control, where the system fails to enforce proper authorization boundaries.
From an operational impact perspective, this vulnerability poses severe risks to smart home security and system reliability. An unauthenticated attacker can not only cause denial-of-service conditions but also potentially alter critical system configurations that affect device connectivity, security protocols, and overall system functionality. The attack surface extends beyond simple service disruption to include potential data integrity compromise and unauthorized access to connected IoT devices within the smart home ecosystem. This vulnerability directly maps to ATT&CK technique T1190, which covers exploitation of remote services, and T1499, which addresses network denial of service attacks, making it a particularly dangerous weakness in the system's security posture.
The mitigation strategies for this vulnerability should focus on implementing robust authentication mechanisms for all configuration endpoints, including mandatory user authentication and proper authorization checks. System administrators should immediately disable or restrict access to the setconf endpoint until proper authentication controls are implemented. Network segmentation and firewall rules should be configured to limit access to this endpoint to trusted administrative networks only. Additionally, input validation and sanitization measures must be implemented to prevent malformed requests from causing system instability. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other system components, ensuring comprehensive protection against unauthorized access and configuration changes that could compromise the entire smart home infrastructure.