GL.iNet GL-MT3000 OpenVPN Client Command Injection
First seen Aug 4, 2026 · Updated Aug 4, 2026 · CVSS 9.8
A critical command injection vulnerability exists in the ovpn-client.so plugin of GL.iNet GL-MT3000 routers (up to firmware 4.4.5), reachable via the /cgi-bin/glc endpoint. An attacker can remotely inject OS commands through the Hostname parameter of the get_recommend_config function, potentially achieving full device compromise. The exploit has been publicly disclosed, increasing the likelihood of active exploitation.
Technical Analysis
CVE-2026-18602 stems from insufficient input sanitization of the Hostname parameter passed to ovpn-client.get_recommend_config within the ovpn-client.so native plugin, exposed through the /cgi-bin/glc CGI interface. Because the parameter is used to construct a system-level command (likely for OpenVPN configuration retrieval), an attacker can inject arbitrary shell commands executed with the privileges of the CGI process, typically root on embedded Linux router firmware. The attack is remotely exploitable and requires no authentication, and public disclosure of the exploit significantly raises the risk of mass scanning and automated exploitation. Organizations that deploy GL-MT3000 routers as edge/network infrastructure for remote AI agent deployments, IoT gateways, or branch offices running agentic automation could see these devices used as an initial foothold for lateral movement, credential harvesting, or man-in-the-middle interception of API keys and agent traffic traversing the compromised network segment.
Affected Systems
GL.iNet GL-MT3000 travel routers running firmware versions up to and including 4.4.5, specifically the ovpn-client.so Native Plugin component accessed via /cgi-bin/glc
Indicators of Compromise
- Endpoint: /cgi-bin/glc
- Function: ovpn-client.get_recommend_config
- Parameter: Hostname (command injection vector)
- Component: ovpn-client.so
Remediation Steps
- 1
Apply Firmware Update
Upgrade GL-MT3000 devices to a patched firmware version once released by GL.iNet; monitor vendor advisories closely given confirmed vulnerability disclosure.
- 2
Restrict Management Interface Access
Disable or restrict remote access to the router's CGI/web management interface, limiting it to trusted internal networks or VPN-only access.
- 3
Network Segmentation
Isolate GL-MT3000 devices from sensitive network segments, including systems hosting AI agent infrastructure, API keys, or RAG pipelines, to limit lateral movement if compromised.
- 4
Monitor for Exploitation Indicators
Inspect logs for anomalous requests to /cgi-bin/glc with suspicious Hostname values containing shell metacharacters (e.g., ;, |, &&, $()).
- 5
Disable Unused OpenVPN Client Features
If the OpenVPN client functionality is not required, disable the ovpn-client.so plugin or associated services to reduce attack surface.
CVE / Advisory IDs
Industries Most Exposed
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