CVE-2026-18684 in GL-MT3000
Summary
by MITRE • 08/04/2026
A weakness has been identified in GL.iNet GL-MT3000 up to 4.4.5. This issue affects the function remove_profile of the file /cgi-bin/glc of the component modem.so. This manipulation causes command injection. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure and confirmed the existence of the vulnerability.
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Analysis
by VulDB Data Team • 08/04/2026
The vulnerability identified in GL.iNet GL-MT3000 routers running firmware versions up to 4.4.5 represents a critical command injection flaw within the modem.so component of the device's web interface. This weakness exists specifically within the remove_profile function of the /cgi-bin/glc script, which serves as a gateway for modem configuration management. The vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly handle user-supplied data when processing profile removal requests. Attackers can exploit this flaw by crafting malicious input parameters that bypass normal processing routines, allowing arbitrary command execution on the affected device.
The remote exploitability of this vulnerability places it within the realm of serious security concerns, as it does not require physical access or local network privileges to execute. The attacker can initiate exploitation from any location with network connectivity to the router's web interface, making it particularly dangerous for enterprise and residential deployments where such devices may be exposed to untrusted networks. This remote attack vector directly aligns with tactics described in the MITRE ATT&CK framework under T1203 - Exploitation for Client Execution and T1059 - Command and Scripting Interpreter, where adversaries leverage web-based interfaces to execute malicious commands on target systems.
The technical impact of this vulnerability extends beyond simple command execution, as it enables attackers to gain full administrative control over the affected router. This access allows for complete network configuration manipulation, including modification of firewall rules, DNS settings, and routing tables. The compromised device can then be used as a pivot point for further attacks within the local network or as a command and control server for exfiltration activities. The vulnerability's presence in the modem.so component suggests that it may affect core networking functionality, potentially disrupting legitimate network services while enabling malicious operations.
Security researchers have confirmed that this vulnerability has been publicly disclosed and is actively being exploited in the wild, with exploit code readily available to threat actors without specialized knowledge of the underlying system architecture. The vendor's early acknowledgment of the issue indicates recognition of its severity and potential impact on deployed devices. According to CWE classification, this vulnerability maps to CWE-77 - Improper Neutralization of Special Elements used in a Command ('Command Injection'), which is a well-documented weakness that has been exploited across numerous network devices and embedded systems. The combination of remote exploitability, administrative privileges, and widespread availability of exploitation tools makes this vulnerability particularly dangerous for organizations relying on GL.iNet equipment.
Organizations should immediately implement mitigations including firmware updates from the vendor, network segmentation to isolate affected devices, and implementation of web application firewalls to detect and block malicious requests. The device configuration should be reviewed to disable unnecessary services and ensure that only authorized users have access to administrative interfaces. Regular monitoring for suspicious network activity and implementing intrusion detection systems can help identify exploitation attempts. Additionally, network administrators should consider implementing access controls at the router level to restrict remote management access and establish secure communication channels only through trusted networks. The vulnerability demonstrates the critical importance of input validation in embedded system components and highlights the need for comprehensive security testing of web interfaces in network appliances.