CVE-2018-9162 in Smart Home Device
Summary
by MITRE
Contec Smart Home 4.15 devices do not require authentication for new_user.php, edit_user.php, delete_user.php, and user.php, as demonstrated by changing the admin password and then obtaining control over doors.
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Analysis
by VulDB Data Team • 01/20/2020
The vulnerability identified in CVE-2018-9162 affects Contec Smart Home 4.15 devices where multiple user management scripts lack proper authentication mechanisms. This critical flaw exists in the web interface of these smart home security devices, specifically in the new_user.php, edit_user.php, delete_user.php, and user.php scripts. The absence of authentication requirements for these administrative functions creates a severe security weakness that directly impacts the device's access control and overall security posture. These scripts are designed to manage user accounts and permissions within the smart home system, yet they fail to verify the identity of users attempting to perform administrative actions.
The technical implementation of this vulnerability stems from improper access control design patterns where the application does not enforce authentication checks before allowing modifications to user accounts. This represents a classic failure in the principle of least privilege and violates security best practices for web application development. The flaw allows any remote attacker to exploit these unauthenticated endpoints and perform administrative operations without proper authorization. The vulnerability is particularly dangerous because it enables attackers to change administrative passwords and subsequently gain full control over the connected door systems, effectively compromising the entire security infrastructure of the smart home environment.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete system compromise and physical security breaches. An attacker who successfully exploits this vulnerability can manipulate user accounts to escalate privileges, create new administrator accounts, or modify existing ones to gain persistent access to the smart home system. The ability to change admin passwords directly undermines the authentication mechanism that should protect access to the device's administrative interface. Furthermore, the exploitation of this vulnerability can lead to unauthorized door control, potentially allowing attackers to open secured entrances without proper authorization, creating a significant risk for residential and commercial security systems.
Organizations and individuals using Contec Smart Home 4.15 devices should immediately implement mitigation strategies to address this vulnerability. The most effective immediate solution involves implementing network-level access controls and firewall rules to restrict access to these administrative endpoints from untrusted networks. Additionally, vendors should be encouraged to provide firmware updates that enforce proper authentication mechanisms on all user management scripts. This vulnerability aligns with CWE-284, which describes improper access control, and corresponds to ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting. The lack of authentication checks in these scripts demonstrates a failure in the application's security architecture and highlights the importance of implementing robust access control mechanisms in embedded systems and IoT devices.