CVE-2016-15056 in EVW3226
Summary
by MITRE • 11/15/2025
Ubee EVW3226 cable modem/routers firmware versions up to and including 1.0.20 store configuration backup files in the web root after they are generated for download. These backup files remain accessible without authentication until the next reboot. A remote attacker on the local network can request 'Configuration_file.cfg' directly to obtain the backup archive. Because backup files are not encrypted, they expose sensitive information including the plaintext admin password, allowing full compromise of the device.
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Analysis
by VulDB Data Team • 11/16/2025
The CVE-2016-15056 vulnerability affects Ubee EVW3226 cable modem/routers with firmware versions up to and including 1.0.20, representing a critical security flaw in network device configuration management. This vulnerability stems from improper handling of configuration backup files within the device's web interface, creating a persistent security risk that extends beyond typical authentication boundaries. The flaw allows unauthorized access to sensitive system information through a simple HTTP request, fundamentally undermining the device's security posture.
The technical implementation of this vulnerability involves the firmware storing configuration backup files in the web root directory immediately after generation, making them directly accessible via standard web protocols. These backup files remain accessible without any authentication requirements until the next device reboot, creating an extended window of opportunity for exploitation. The specific file name 'Configuration_file.cfg' serves as a predictable access point that attackers can target directly, bypassing normal authentication mechanisms entirely. This design flaw represents a violation of secure configuration management principles and exposes critical system information through insecure file placement.
The operational impact of this vulnerability extends far beyond simple information disclosure, as the backup files contain plaintext administrative credentials that provide complete control over the affected device. Remote attackers within the local network can exploit this vulnerability without requiring any specialized tools or advanced techniques, making it particularly dangerous in environments where network segmentation is not properly implemented. The exposure of plaintext passwords enables attackers to perform full device compromise, including configuration changes, network modifications, and potential lateral movement within the network infrastructure. This vulnerability directly maps to CWE-312 (Cleartext Storage of Sensitive Information) and CWE-287 (Improper Authentication) categories, representing multiple security weaknesses in a single flaw.
The security implications of this vulnerability align with ATT&CK technique T1210 (Exploitation of Remote Services) and T1078 (Valid Accounts) as attackers can leverage the exposed administrative credentials to gain persistent access to the network infrastructure. Network administrators face significant risk as this vulnerability can lead to complete device compromise, potentially enabling attackers to establish persistent backdoors or use the device as a pivot point for accessing other network resources. The vulnerability's persistence until reboot creates an ongoing risk that requires immediate remediation, as the window for exploitation remains open indefinitely. Organizations should implement immediate network segmentation, disable unnecessary services, and deploy network monitoring to detect potential exploitation attempts. The recommended mitigation includes firmware updates to address the insecure file handling, implementation of proper access controls, and regular security assessments to identify similar vulnerabilities in network infrastructure devices.