Cline Hub Dashboard WebSocket Origin Validation Bypass

Detection Guidance

This vulnerability can be detected by monitoring WebSocket connections to the Cline Hub dashboard's /browser endpoint, especially those originating from unexpected or external origins. Since the issue involves acceptance of WebSocket connections without validating the Origin header, you can look for WebSocket upgrade requests to ws://127.0.0.1:8787/browser or similar local addresses that do not include proper Origin headers.

To detect potential exploitation attempts or presence of the vulnerable service, you can use network inspection tools or commands to observe WebSocket traffic and HTTP headers.

• Use netstat or ss to check if the Cline dashboard server is listening on the expected port (default 8787): - netstat -an | grep 8787 - ss -tuln | grep 8787
• Use curl or similar tools to attempt a WebSocket handshake and inspect headers: - curl -i -N -H "Connection: Upgrade" -H "Upgrade: websocket" -H "Origin: http://malicious.example.com" http://127.0.0.1:8787/browser
• Use browser developer tools or WebSocket inspection tools to monitor WebSocket connections to the /browser endpoint and check if Origin headers are missing or not validated.

If you observe WebSocket connections accepted from unexpected origins or without proper Origin validation, or if the ROOM_SECRET environment variable is unset on local binds, your system may be vulnerable.

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Executive Summary

This vulnerability affects the Cline Hub dashboard server prior to version 3.0.30. The server accepts WebSocket connections on the /browser endpoint without validating the Origin header. When the ROOM_SECRET is unset for local 127.0.0.1 binds, the isAuthorizedBrowserRequest() function allows attacker-controlled websites to send desktopCommand frames. These frames can read the workspace state, change MCP and provider settings, and trigger command execution if a provider or model is configured.

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Impact Analysis

This vulnerability can have a severe impact as it allows attackers to remotely execute commands, read sensitive workspace information, and modify critical settings within the Cline environment. This can lead to unauthorized access, data manipulation, and potentially full compromise of the affected system.

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Mitigation Strategies

To mitigate this vulnerability, upgrade Cline to version 3.0.30 or later, where the issue is fixed.

Ensure that the ROOM_SECRET environment variable is set when binding the dashboard server to local 127.0.0.1 addresses to prevent unauthorized access.

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Compliance Impact

The vulnerability allows attacker-controlled websites to send desktopCommand frames that can read workspace state, mutate settings, and trigger command execution. This can lead to unauthorized access and manipulation of sensitive data and system configurations.

Such unauthorized access and potential data exposure or alteration could negatively impact compliance with standards and regulations like GDPR and HIPAA, which require strict controls over data confidentiality, integrity, and access.

However, the provided information does not explicitly mention compliance impacts or specific regulatory considerations.

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