CVE-2021-47708 in Smart Home IoT Control System
Summary
by MITRE • 12/10/2025
COMMAX Smart Home System CDP-1020n contains an SQL injection vulnerability that allows attackers to bypass authentication by injecting arbitrary SQL code through the 'id' parameter in 'loginstart.asp'. Attackers can exploit this by sending a POST request with malicious 'id' values to manipulate database queries and gain unauthorized access.
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Analysis
by VulDB Data Team • 12/10/2025
The COMMAX Smart Home System CDP-1020n represents a significant security vulnerability through CVE-2021-47708, which manifests as an SQL injection flaw in the system's authentication mechanism. This vulnerability resides within the loginstart.asp component where the 'id' parameter is processed without adequate input validation or sanitization. The flaw enables attackers to manipulate database queries by injecting malicious SQL code directly through the username field during authentication attempts. The vulnerability specifically affects the system's ability to properly validate user credentials, creating a pathway for unauthorized access to the smart home system's administrative functions.
The technical exploitation of this vulnerability follows a classic SQL injection attack pattern where attackers craft malicious payloads targeting the 'id' parameter in POST requests to loginstart.asp. When the system processes these inputs without proper parameterization or input filtering, the injected SQL code gets executed within the database context, potentially allowing attackers to bypass authentication mechanisms entirely. This type of vulnerability falls under CWE-89 which categorizes SQL injection as a critical weakness in software applications that handle database queries with user-supplied data. The attack vector is particularly dangerous because it targets the authentication layer, which serves as the primary gatekeeper for system access.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential full system compromise and data breaches within the smart home environment. An attacker who successfully exploits this vulnerability could gain administrative privileges to control all connected devices, modify system configurations, access stored user credentials, and potentially exfiltrate sensitive data from the home network. This represents a critical risk for residential and commercial users who rely on the system for security monitoring and automation. The vulnerability's impact is amplified by the nature of smart home systems which often contain sensitive personal information and control critical infrastructure such as lighting, heating, and security systems.
Mitigation strategies for CVE-2021-47708 should prioritize immediate patching of the affected system components and implementation of proper input validation mechanisms. Organizations and users should ensure that all database interactions employ parameterized queries or prepared statements to prevent SQL injection attacks, which aligns with the defensive measures recommended in the ATT&CK framework under technique T1190 for exploitation of vulnerabilities. Network segmentation and access control measures should be implemented to limit the potential impact of successful exploitation, while monitoring systems should be deployed to detect anomalous authentication patterns. Additionally, regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other system components, particularly within the authentication and input validation layers. The vulnerability demonstrates the importance of adhering to secure coding practices and following industry standards such as those outlined in OWASP's top ten security risks, which emphasize the critical need for proper input validation and output encoding in web applications.