CVE-2019-6273 in GL-AR300M-Lite
Summary
by MITRE
download_file in GL.iNet GL-AR300M-Lite devices with firmware 2.27 allows remote attackers to download arbitrary files.
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Analysis
by VulDB Data Team • 09/09/2024
The vulnerability identified as CVE-2019-6273 affects GL.iNet GL-AR300M-Lite devices running firmware version 2.27 and potentially other versions. This represents a critical security flaw in the device's web interface that enables remote attackers to exploit a directory traversal vulnerability through the download_file functionality. The issue stems from inadequate input validation within the firmware's file handling mechanisms, allowing unauthorized access to sensitive system files that should remain protected from external retrieval.
This vulnerability operates through a classic path traversal attack vector where malicious actors can manipulate the download_file parameter to access files outside the intended download directory. The technical implementation involves insufficient sanitization of user-supplied input, which permits attackers to craft malicious requests containing directory traversal sequences such as ../ or ..\ that bypass normal file access controls. The flaw exists in the device's web server component that processes file download requests without proper authorization checks or path validation, making it possible for remote adversaries to retrieve configuration files, system logs, authentication credentials, and other sensitive data stored on the device.
The operational impact of this vulnerability is severe as it provides attackers with unauthorized access to potentially sensitive system information that could be used for further exploitation or lateral movement within network environments. An attacker who successfully exploits this vulnerability could obtain device configuration files containing network settings, user credentials, or other system parameters that might reveal network topology information or facilitate additional attacks. The remote nature of this exploit means that attackers do not require physical access to the device or network presence to carry out the attack, making it particularly dangerous for devices deployed in untrusted network environments or public locations.
The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. This classification indicates the fundamental flaw in how the device handles file paths and validates user input. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including T1083 (File and Directory Discovery) and T1071.004 (Application Layer Protocol: DNS) as attackers may use the retrieved information to plan further attacks or establish command and control communications. The security implications extend beyond simple information disclosure to potentially enable more sophisticated attacks such as privilege escalation or device compromise.
Organizations should immediately implement mitigations including firmware updates from GL.iNet if available, network segmentation to isolate affected devices, and firewall rules that restrict access to the device's web interface from untrusted networks. Network administrators should also monitor for unusual file access patterns and implement intrusion detection systems that can identify directory traversal attempts. The most effective long-term solution involves updating to firmware versions that properly validate and sanitize all user input before processing file operations, ensuring that path traversal sequences are rejected and that access controls are properly enforced. Additionally, implementing network-based access controls and disabling unnecessary web services on the device can significantly reduce the attack surface and limit the potential impact of such vulnerabilities.